First build a (wooden) frame. I used dark plywood sheets and glued them together. Then use some bars for legs or that table.
The project was made long time ago therefore the image quality is poor (old digital camera)
Then I bought an acrylic glass sheet. The company who sold me that part cut it into shape for me. It must be stable to hold drinks and other good which someone puts on the table. Therefore I chose a plate with a thickness of 20mm. It's expensive (200Eur) but it looks nice.
I first mounted another piece of plywood orthogonal so that I could put some IR led's in.
These IR LED's could be used for detecting touches. If you like, read the theory here: http://reactable.com
You can see the light of the IR-Diodes in the images above.
Because I ran out of money, I changed the idea and just turned it into a multimedia table to show informations. The big screen looks nice, too.