Best table top materials?

1/2 inch Baltic Birch!

No matter what you do with tubular track, mount the track by using weather proofing foam strip material slightly higher than the height of the ties. Stick the tacky side down. The track won’t move and the foam acts as a noise deadening agent because the track is slightly suspended and not transferring noise to the table.

Are you suggesting placing foam strips under each tie or under the rails, too?

What, me worry?

Movement and vibration cause sound. 

Solution, IMO:  Advantech, available thru 84 lumber is the new standard in sub floors.  Extremely flat, low responsive to moisture, very stiff, 3/4" about $30.  Can be used on 24" and 32" centers.   Heavy.  I have been using this for the last 8 years to much success.  I top it with 1/2" Homasote, then cork or Homabed road bed. 

I have tried many other combinations but this works best for me.

Baltic Birch slow growth northern plywood in a multiply format is excellent at about 170% the cost.  Have had a few delamination claims though. 

Alfred E Neuman posted:

Are you suggesting placing foam strips under each tie or under the rails, too?

What, me worry?

Just the ties.