I've had a lot of questions in regard to our pvc pipe sensory tables and plexi-glass table top.
I actually made a handout for one of my training sessions in regard to both our sensory tables and our light tables. You can download a pdf version of it here. (I don't have dimensions, as it will all depend on the bin you choose for the table. Perhaps I will get a better tutorial up soon with the exact dimensions if you order your tub from Home Depot.)
We actually have 3 tables. The one you have been seeing recently with the plexi-glass on top of it is made with 1 1/4" diameter pvc pipe and has a little bit different design than the one shown on the handout. (When I switched to a different cement mixing tub, I also switched the design a little bit). I found a lot of inspiration from other sites, and merged ideas to come up with my design.
In regard to the plexi-glass table top we have.... Well, all it is are two sheets of plexi glass that I place over the frame of the table. They are not connected to it in any way. I'll have to measure the plates for you when I get home, but they are upcycled plates that we took out of some of the cribs that were donated by a friend of mine because they could no longer be used with the new standards for cribs. We took them apart, and have upcycled some of the pieces into things, using the plexi glass as mentioned and making a writing desk here.
I hope this answers most of your questions! One of the great things about the pvc pipe table is that it can easily come apart to be stored. If you are anything like me... storage can be an issue! So, having a table that can easily come apart and be stored, yet be sturdy enough for exploration is ideal!