Even though it is totally unclear what you want to do with the tables, there is a basic approach to visiting all the tables in a document:
var oDoc = app.ActiveDoc;
var oTable = oDoc.FirstTblInDoc;
while( oTable.ObjectValid( ) )
{
// do something with the oTable object
oTable = oTable.NextTblInDoc;
}
Note that this linked list also contains the tables on the reference pages, so you will have to check the table tag to see if it is a table you need to process. Nomally the tables on your body pages will use a format tag that is not also used by the tables on the reference pages (this linked list is one of the reasons to stick to that rule of thumb).
To check the format of the table, use oTable.TblTag.
To figure out what to do with the contents of the table, use the FrameMaker Scripting Guide. Look up the Tbl object, see which children it has, look up the properties of those child objects, etc. Make small steps, add lots of alerts in your scripts to see if each step works, then proceed with the next little step. It will become easier when you learn from initial mistakes.
Good luck