Very nice summary of some best practices. Thank you for a great article! I’ll add that scrolling is important; if you have an table that’ll exceed the height of the viewport, having the headers follow as you scroll vertically is a must: the user should always be able to see the headers corresponding to the row they’re looking at. Same for wide tables, for which you need a horizontal scrollbar: identify the left-most column(s) that need to be fixed in place as you scroll horizontally, and the user will have context no matter where they’ve scrolled. Of course, the BEST approach is to not require horizontal scrolling in the first place, but with financial web sites (my current focus) it’s a bit hard to avoid. Providing a download option is also a nice idea so users can manipulate the data on their own in a spreadsheet app of their choice.