I was looking into homasote for the top of the two tables and table bridge. I'll be using KATO track and it seems like a good idea to have some sound dampening between the track and plywood deck. I hope to be able to snag a 4x8 sheet at home depot and have it cut the same way as I had the ply cut. (Mostly so I could fit it into my Yaris! :) ) However, it looks like it may be a hard item to find and even if the Home Depot does have it in stock, they may not want to cut it.
Another option is Homabed, but it looks like it's more of a track fit item. I wanted to cover the entire surface. We'll see.
I'm going to roll over there to check it out either way. What better way to spend a lunchtime!