After updating Discourse today to troubleshoot a strange issue that emerged after the previous update, I noticed this:
Before posting, I tried:
Clearing browser cache.
Incognito mode.
Closing and opening browser.
and admin/?safe_mode=1&disable_all_themes=1&disable_plugins=1
I see the icon on my local instance, but a component or plugin may have added it. Likely from Discourse AI, actually!
I guess discourse-table is missing from the default additional SVG icons.
Maybe. I have not added Discourse AI yet. I’m struggling enough to keep up with mostly vanilla Discourse. 
I made a PR to fix it:
Approved. Thanks @Arkshine!
