If I’m understanding what you’re asking — In the new beta (1.2.1) check under edit > rules (? pretty sure. at work and not in front of the prg) There you should at least be able to filter unwanted items into a dump tabble. Haven’t played with it much yet, but I don’t see a way to exclude files in auto-tabbling.
As to filtering things out of your results; in the file window after you’ve done your basic search, right click on a tag (under the file) or on a tabble in the suggested column and there is an option to exclude files with that tabble from the results. (only place the option shows up at the moment so far as I can see)
Remember, this beta is the first implimentation of a very powerful feature so it will get dialed in over the next few weeks/months to get more useful and specific.
Don’t get me started on nested Tabbles, though. Something we’ve been hoping for for a while now… 🙂
Hope that helps.