First, is this an inside table or an outside table, and if it is outside does it get below freezing where you are?
You could use thinset, but I prefer mastic or epoxy, unless the temperature will drop below freezing and then it must be epoxy.
http://www.defusco.com/glues-epoxy-polyester-etc-tenax-crystal-mastic-c-82_321.html this is mastic
http://www.defusco.com/rivo-knife-grade-epoxy-p-1427.html this is epoxy
For grout you can use a nonsanded grout
The sealer would depend on whether you are trying to color enhance the stone or not. Since it is tumbled
my guess is not so you should seal it with Hydrex by Tenax,
http://www.defusco.com/glues-epoxy-polyester-etc-hydrex-sealer-c-82_502.html this is Hydrex
Mark