I'm working on a large scale battlefield encounter, and wanted to add "battlefield events" similar to those added in the recent Dragonlance supplement to occur at the end of each round. Does the Encounter Builder support snippet codes so I can add a table containing these events to my encounter description?

No, only things with snippet fields support snippet codes. So far that is restricted to subclass features, race/species traits, feats, and any Actions attached to features, traits, and feats.

However, snippets are not required for tables. To insert a table, please follow the instructions in the General Homebrew FAQ #12: (https://www.dndbeyond.com/forums/dungeons-dragons-discussion/homebrew-house-rules/131411-a-homebrewers-how-to-faq). It would follow the same principles.

I was wrong. Sorry.

Well I don't know the distinction between snippet codes and other formatting, but the method described on that FAQ just pastes the plaintext of the table into the description.

The encounter builder doesn't show the editor controls, so can I assume this means I can't insert a table?

Ahh, no. My apologies. I was thinking of the campaign notes, not the encounter builder itself.

PS- For future, this is all the info about snippets: (https://www.dndbeyond.com/forums/dungeons-dragons-discussion/homebrew-house-rules/25930-using-snippet-codes-in-your-homebrew).