Support tables in cards (Gist provided)

Prerequisites

• I have searched for duplicate or closed feature requests
• I have read the contributing guidelines

Proposal

Hello,

I'd like to suggest to officially support tables inside of cards. I'm aware that this comes with a lot of edge cases to consider. Cards are a great way to display mixed content or even just work as a visual container. Tables should be one element, as it allows to annotate tables with additional context in the same visual container. There's another ticket #17395, but that one's locked, so I cannot add a comment to that.

I tried to come up with a fix and I think it is pretty clean and catches most of the cases a user could have. At least in my project, I couldn't find a combination that doesn't work with my snippet.

Please have a look at my gist:
https://gist.github.com/tinyoverflow/999c7797ce51582ea4481b2501e7ad20

Motivation and context

In my current project, I make heavy use of tables inside of cards. They don't look good by default. Researching this topic resulted in a lot of people with this issue, so I decided to try to tackle this one.

No source file or test is named. Start by reviewing the provided Gist and the related issue #17395, then inspect the existing card and table styling; done should mean tables display appropriately inside cards, including the edge cases covered by the agreed approach.