One can certainly bond them together with a structural adhesive like SikaFlex.
(That would also likely provide some container layer dampening.)
A grinding wheel to knock down high points and then another layer if adhesive to hold the top on can make them flat in a similar way to how a shoe orthotic provides a platform for the foot.
One could probably use a layer of sorbethane type of stuff.
At some point if the floor is vibrating, then keeping that from telegraphing up through the structure can be helpful.
concrete (cinder) block tower with wood chopping block for turntable stand
Any suggestions from users who have done, or contemplate doing this. I looked at concrete blocks at Lowes last night. I made two stacks of 3 side by side, plus a solid block (without the center openings) as the top block. This gave me about 34" in height. Then the thought is either a Walnut or Bamboo chopping board for a top shelf. I would use four cork or cork/rubber sandwich (2"X 2") squares to couple the wood chopping block to the concrete tower. I am also considering an Isoacoustics platform as a more expensive alternative. Fire away....?