Are tables inside tables a good idea in the right circumstance

Question

I found myself wanting to put a table in a table. I had a momentary war flashback of legacy webpages and email html templates and was about to shelve the idea, but then I considered that it kind of made sense in this case.

I have a table showing tabular game information. There are 2 players in a game. I want to show their tabular information in the game table.

Is this a good situation for using a table in a table? Is it semantic HTML? Are tables inside tables even valid in HTML5?

Answer 1

Semantic HTML is about accurately describing the semantic structure of your document. If your document contains tabular data, then use a table. If your document contains tabular data which is itself tabular, then use a table-in-a-table.

In fact, I would argue that not using a table to represent tabular data violates semantic HTML.

This isn't SQL, the First Normal Form (data must be atomic) doesn't apply. (Oh, and BTW, there are Relational Databases called (NF)² for Non-First-Normal-Form which allow exactly that: columns whose type is a table.)

The Content Model of a <td> element is Flow Content, which includes the <table> element.