I used to love working with vitreous (venetian) tiles (mostly 3/4"). Here is my Flickr link - the first 3 projects are mosaiced totally in vit. Stained glass is sometimes thinner than vit so you may have to build it up so it is level for a table top.

http://flickr.com/photos/88594345@N00/

OK - so I posted without thoroughly reading your post - "wood table". Hopefully this will be used indoors only! Wood just isn't mosaic-friendly! Yes, you can use marine ply (5 ply thick) but wood on the verticle isn't good for a mosaic. If you still want to use this (for indoors), you will need to score and seal the wood before mosaicing (slap me if you already knew this - ;) - I like to use Kilz (water-based).
Jane

EEK, no, Platebreaker, I was going to use it under a covered patio. Actually, it's really a chair minus the back that I "dumpster-dived". It's very thick since it was a chair. I just really wanted to make something nice out of something that no one wanted. I kind of felt sorry for it, all alone it the garbage. LOL I was going to paint the legs a very bright color. Maybe, I should just sand it off and just paint it instead. Jeanette

Wood absorbs moisture ...causing your tiles to pop off. No matter how much you seal it ( just takes longer sometimes)

There is a height difference between vit. tiles and stained glass, so that can be an issue, too.