Ensure that tables have necessary markup to be transformed by accessible browsers and other user agents.
Tables should be used to mark up truly tabular information ("data tables").
Content developers should avoid using them to lay out pages ("layout tables").
Tables for any use also present special problems to users of screen readers
Some user agents allow users to navigate among table cells and access header and other table cell information. Unless marked-up properly, these tables will not provide user agents with the appropriate information.