Wikipedia:Table dos and don'ts

Tables are a great way to present data.
When you work with tables:
DO:
Use wikitables, not HTML tables.
Use class="wikitable" to apply standard style.
Use short, self-explanatory captions and headers.
Use CSS classes, not inline attributes, to set table style.
Make columns sortable as appropriate.
DON'T:
Don't use tables for visual layout.
Don't use color alone to convey information.
Don't nest tables if avoidable.
Don't use scrolling tables in articles.
Don't split up sortable tables.

See also Edit