"If I had to guess this... table thing is where we put our 'riches', whatever they are," Keyleth offers.

"Nangnang teaches us to serve only ourselves... whoever is richest bring me your gifts..." she repeats aloud a couple of times, thinking over what course of action the words might suggest.

"So, I suppose Nangnang favors greed and opposes sharing, right? In which case, he would presumably look favorably on someone who took this treasure for themselves. Maybe the treasure here is meant as part of the riches? It's possible you're right about the spear, Kirinar, but maybe it's just a matter of one person collecting as much of the loot as possible --- that way there's no doubt who the richest is."

"Ahbut Keyleth I'm thinking collecting all of Nangnang's treasures in order to demonstrate our wealth may not be the best idea you've ever had. Taking it may have some unknown but completely forseeable outcomes" Dr A responds to Keyleyth's sugeestion. He looks over at Timber "ahbut your people my young furred friend have a reputation for collecting things that don't belong to them which you find interesting. Can I suggest you resist such urges?:

"I think the treasure that we can see here is a distraction. If we serve only ourselves, then I am my greatest treasure. Maybe one person needs to stand on the table. But I don't know which one of us would be 'richest' for this challenge..."

Keyleth scrunches up her face in thought, pondering what Dr. A said. "You might be right, although if we are moving the treasure from over there to over here as an offering of sorts... I'm just not sure how we determine who is unambiguously 'richest' otherwise... I'm certainly open to other ideas," she adds, looking toward Kirinar, and hesitating, before adding, "though I'm not sure the answer is likely to be 'somebody jump on the table'... No, uh... no offense intended," she looks awkwardly at the floor.

Seeing no other alternative, and hearing no other ideas, the fighter pulls out his belt pouch with all of his coins and precious stones and sets them on the table in front of the door. "I am the richest one here! Let me in!"

Nothing happens.

Kirinar shrugs and collects his small treasure. "Well, now we know THAT isn't it!"

Dr A watches as nothing happens and then comments "ahbut this old brain can't work it out, but perhaps if I sleep on it and seek Mystara's guidance in the morning then something may be made a bit clearer?"

As a hint to try and get this moving again, you've already found the solution.  You just haven't tried anything yet except Kirinar's single attempt.

Dr A searches the complex thoroughly for a spear or something that could be a spear = 24 

Dr A is unable to find a spear.

"Well, process of elimination... should we try my idea next?" Keyleth suggests, and begins to circulate around the shrine and gather up treasure, and bring it to the stone table (doing her due diligence to check for traps and such along the way).

Keyleth collects armfuls of treasure found within the shrine and steps forward to place the treasure on the table.  At first nothing happens.  She then turns to Timber and with a stern look tells him to empty his pockets.  With a sheepish look the tabaxi empties a couple pockets of treasure he happened to pick up in the shrine, quite by accident.  With Keyleth being the only one in the group now holding any treasure from the shrine the door before her grinds open. 

In the middle of this dusty room, a stone cube rests on a pedestal carved and painted to resemble a squat, humanoid frog.

Seeing no danger, Keyleth quickly enters the room and grabs the cube off of the pedestal.  She returns to her companions, a triumphant look on her face.

"That is all 9 cubes." Artus says.  "We should be able to gain entry to the Tomb of the Nine Gods now."

Keyleth feels her heart race at the mention of the tomb. "That is what we came here for..." she says. "But... maybe we should get some rest first so that we're going in at full strength?"

"Ahbut perhaps in the morning?" Dr A queries

Keyleth nods. "That's what I was thinking."

It is early morning now as you had rested overnight and then went to the shrine.

Having secured the 9 cubes you make your way to the entrance that you had found earlier.

Near the base of the cliffs, a fifteen-foot-tall obelisk (1) of cracked stone is draped with vines and black moss. Clearing the vines and moss from the south face of the obelisk exposes a message carved into it in Common.

Behind it, you see a dark passageway (3) obscured by withered creepers.

A short tunnel ends at a slab of worked stone, whose edges are marked by relief carvings of grinning skulls. Four lines engraved at the center of the slab cross one another to form a star, with both ends of each line marking the location of a cube-shaped cavity cut into the door — eight cavities in all.

A second, smaller tunnel burrows into the base of a cliff to the east (2). Alcoves run the length of a narrow tunnel, each one featuring a bestial statue standing or squatting above a basin of oil.

The statues depict the nine trickster gods, with each facing pair of alcoves dedicated to two trickster gods who oppose each other. Moving down the hall from west to east, the opposing statues depict Moa (jaculi) and Wongo (su-monster), I’jin (almiraj) and Obo’laka (zorbo), Papazotl (eblis) and Kubazan (froghemoth), and Nangnang (grung) and Shagambi (kamadan).

Each statue is 3 feet tall and can’t be moved from its pedestal. When any of you carrying a puzzle cube enters the tunnel, the oil basin matching the cube’s trickster god bursts into flame. Only eight trickster gods are initially visible; the statue of Unkh (flail snail) is hidden behind a secret door at the end of the tunnel, though it functions the same as the others.

A golden pendant shaped like an eye hangs on the Unkh statue.

Three stone gargoyles watch you from narrow ledges carved into the cliff side. Each has the face of a bearded devil, its mouth agape in a silent scream.

Pulling aside the heavy undergrowth, you uncover an archway in the cliff face (4a). Stone skulls peer down from the lintel, and old bones litter the threshold. As light strikes the entrance, a swarm of bats screeches out from within. A slab of worked stone blocks the overgrown tunnel some twenty feet from the entrance. Grinning skulls mark the edges of the slab, in the center of which are nine cube-shaped cavities arranged in three rows of three.

Quote from Paladin54

It is early morning now as you had rested overnight and then went to the shrine.

OoC: Oh, that's right. I think some people didn't reset their resources on that rest? I was looking at sheets and Timber was down HP and Dr. A was missing some spell slots.

Keyleth visually examines the pendant on the Unkh statue, and then consults Dr. A to take a look too. "This could be important... or it could be bait," she says. "Is there anything Mystra can do to help you figure out which?"

 "Is there anything Mystra can do to help you figure out which?"

"Ahbut certainly my young friend. However first I think we need to seek the blessing and guidance of the Mistress of the Weave." He pauses and then in a far more authoritative -and less folksy voice - than the party has previously heard him speak in he address the heavens "Oh great Mistress of mysteries and  Keeper of the Weave look favorably on your disciple and his companions as we go forth to do your will and seek to once again bring back balance to the weave!"

Dr A examines the statues and says "ahbut Unkh is missing from these eight." What does Dr A recall about Unkh {18} and why might it be missing. He then looks at the plaque what does Dr A recall about Acerak the Eternal {19. Finally he says to Keyleth "ahbut I suspect that donning the mask, which perhaps could be taking on somehow the visage of one of the trickster gods, will allow us to pass those statues" pointing at the gargoyle like creatures "unharmed!"

((If you haven't done a long rest on your sheet go ahead.  Also I added all this information as a reminder as you had already explored this area earlier.  You just couldn't enter the tomb as you did not have the cubes, or enough of them.  The gargoyles statues are not reacting to your presence in the area.))