if you have a table thats close.. but off a little you can use paper or oak tag to shim underneath your ceiling tiles. I have one bench I built that was off a tiny bit..by shimming it with some paper I got the ceiling tiles on top dead perfect...

I don't know if I missed it above but I have a surface that actually isn't ceiling tiles now. Its a denser board..mdf maybe? someone here on RCU recommended it on a thread a few years back...I can just get t pins into it, and they hold like iron...