Hi everyone I was wondering if you guys knew of a way to make a table in a homebrew item, similar to the ones you find on the Staff of Power and the Robe of Useful Items. I'm probably missing something really obvious but any help would be appreciated. 

edit: I've tried copying the two items mentioned above to see how the designers did it but I can't figure it out. 

Have you tried making it in Excel (or similar) and simply copying it to the item?

Look at the copy items in the text boxes containing the tables click on the </> icon. It will show you the HTML code used to make the tables. Just copy that, go to your own item and click the </> icon there and paste the table in changing the values to what you need.

You can also just highlight the table directly and copy, that can work to but I find it less reliable.

Thanks very much for the help everyone, completely forgot you can edit html directly. 

If you're using a pc/laptop do this with Chrome browser.

• Navigate to Collections > Browse Subclasses > click Browse Official Content (upper right screen) > View "class" Details > choose desired subclass from menu on the left screen margin.
• Scroll down to desired table.
• Right click blankspace within table.
• Left click Inspect or View Page Source, I recommend Inspect.
• Page/Tab will split between the Subclass info and the backend html code.
• Make sure the Subclass table you want is visible on the left. 
• Mouse over the html until it highlights the table you want on the left side. Find this and left click one time > look to the left edge of the html viewer to find ... button and left click.
• Menu pops up, clIck EdIt as HTML which will create a subsectioned box. From here Select All (Ctrl + A) of that html code and Copy (Ctrl + C)
• Close HTML viewer
• Return to homebrew subclass settings page
• Paste (Ctrl + V) where you want it 

Use this process copying and pasting whichever relevant info you want. 

I gave a walkthrough (with video) on how to copy/paste a table into your homebrew in the General FAQ #12 (https://www.dndbeyond.com/forums/dungeons-dragons-discussion/homebrew-house-rules/131411-a-homebrewers-how-to-faq).

The problem with the solutions I've seen thus far saying to simply copy paste are vague, and my attempts to do what was specified only ever copied the text and never the tables themselves. If your method works, great, so be it. But it seems to me the better option is to copy/paste the html backend code directly without having to go through a vague & confusing tutorial on how to create from scratch.

Try watching the video I created and read the accompanying explanation and see if that works. You have to grab something from outside of the table too to smag the formatting.

This is pretty old but it was the first result.  The other answer, besides copy-paste, is just to use html.  Click the little </> icon and then you can add tables however you want
<table class="table-compendium table--generic-dice" style="height: 333px;" width="1032" data-content-chunk-id="0943b26f-1ede-4a36-89bc-9760e95acafe"> just look up how html tables work if you need to https://www.w3schools.com/html/html_tables.asp

Then you can basically put in whatever you want.

So I followed this advice and the HTML code now shows on the description. 

Where is the html placed? 

What allows the table - not the html to b visible?

Quote from RakkasanDM >>

So I followed this advice and the HTML code now shows on the description. 

Where is the html placed? 

What allows the table - not the html to b visible?

 
In the text editor click the </> icon. Put the HTML code in where you want the table to appear and click </> again.