Last week, we had the author of TDD for a Shopping Website LiveProject. Friday at 11am Ranch time, Steven Solomon will be hosting a live TDD session just for us. See for the agenda and registration link
I don't think there's a quick and easy way to do this. You'll just have to create a custom TableModel of some sort which will take 2 TableModels and pretend that it's one big one. Still relatively painless, probably < 100 lines.