glue ??? no - EPOXY ? yes.
but - bring it into a climate controlled room, such as where it will be used
and let it acclimate for at least a month. how long did it lay on the concrete ??
it could have soaked up quite a bit of moisture (on one side) from the concrete.
or - it is still not cured (which would take about 2-3 years for a piece that large.
so now, the wood must be stabilized prior to doing any kind of fix.
if you can find a moisture meter, it would be to your advantage to test all surfaces
weekly until you think it has reached its equilibrium. (7-12% M/C is needed).
if you have to FORCE it back together with clamps, it will surely fail in the near future.
"butterfly keys" are not just structural remedies, they also lend character to the wood. you have a beautiful piece of wood !!! do it right and it will last for generations.
this could be the very project if you wanted to expand your woodworking skills.
there are ways to clamp it together so the clamps do their job and don't slide.
do you have any power tools to finish it once you get it stabilized ???
this project is discussed over and over by experts on www.lumberjocks.com
if you need help, drop over there and do the search
for "slab tables".
if you returned it to the seller, you could very well get another slab that will
do the very same - if his whole lot is not cured properly.
and going from his environment to yours, I would expect some physical changes.
sort of like straight lumber from Home Depot going crooked by the time you get it home.
- not a PVA glue. and definitely NOT the Gorilla expanding urethane glue.