Hi Andrea,
I'm not sure I understand what you are trying to do. Can't you simply use teh "where used" function to find out where a certain table is read and/or written? Usually there are only a few calsses / funcation modules that really read a tabel directl. If you that a breajkpoint in those you should be fine.
Another option would be to use a watchpoint together with a free condition. You could for example try something like LINES( ITAB ) > 0.
Christian