Moodle still has a few odd corners where tables are used for laying out things.
Some of these are obviously wrong, other's are more gray areas.
This affects theming and accessability as well as making it trickier to use things on mobile devices.
|Table used for layout on group editing pages
|Table used for layout of group description
|filemanager and filepicker popup windows rely on non-flexible table layouts and do not cope with small screens