Place the three plastic diffuser sheets cut to 17 1/4 x 17 1/4 inches on top of the grid you just layed down. Then, place the Plexiglas (or real glass) cut to the same dimensions as the diffuser sheets on top of the sheets.
Now, you just have to plug in your table and enjoy! Congratulations!!! You just made a light up table with 0 electronic skills used!
If you want, you can continue on for some electrical enhancements to your table if you feel brave enough to do so!