The point here is that through the use of CSS-Tables, it’s possible to create a table-oriented site without screwing over accessibility. Instead of flooding the style-sheets with unused grid-selectors, like what is present with current frameworks (though, debatable), you could do the same with much less definitions using css-tables. CSS Tables make the content act like tables, without skewing the markup to make it actual tables.
For structure: CSS Tables
For Tabular Data: HTML Tables; CSS Tables just don’t have the complete feature-set available to displace HTML tables. Besides that, it’s better to use HTML Tables for tabular data for accessibility and SEO reasons.