Every table starts with 'aiptasia_' Hereafter I will leave out the 'aiptasia' part.
User info stored in _user
All the main page text (past, present, and pre-built) is stored as a blob object in _text table.
_searchindex contains the text,title,ID for all pages that should be searched: the current version of user built pages.
_revision contains simple data on which pages were revised, by whom, when.
_page stores data about each page by page id and title, linking it to the text id found in _text.
_categorylinks store the pageText id, the category name, and the page title.