It's been awhile since I've used TWC. I don't recall tables having tags, so not sure about your table structure.
In any event, in TW5 only tiddlers have tags. When you want to produce a list of tiddlers you will most often use a filter, either inside of a macro such as <<list-links>>, a <$list> widget, or the filter option of the advanced search.
If you have tag Dog and tag Cat, and want to see all the tiddlers tagged "Dog" but not "Cat", you could use something like:
<<list-links "[tag[Dog]!tag[Cat]]">>
If you wanted to see all tiddlers tagged both with Dog and Cat:
<<list-links "[tag[Dog]tag[Cat]]">>
If you wanted to see all tiddlers tagged with either Dog or Cat:
<<list-links "[tag[Dog]] [tag[Cat]]">>
If you wanted to see tiddlers tagged with Dog or Cat but not both:
<<list-links "[tag[Dog]] [tag[Cat]] -[tag[Dog]tag[Cat]]">>
I could go on, but hopefully this gives you the idea. There's an introduction to filters at
tiddlywiki.com:
http://tiddlywiki.com/#Introduction%20to%20filter%20notationGood luck!
Mark