You've imported a Word document with tables. Most of the tables (if not all) have incorrect borders and shading (they vary from the tag definitions).
This assumes you want to force all the tables in the file to have borders and shading exactly as called for in the table tag catalog.
All your tables will now fit the specifications. What has happened is that to change a table's settings it is sufficient to select only the anchor; in other words you do not have to go into each table, select all cells, and apply the settings.