No, but you would be dead.

Grilled cheese sandwiches have a lot of water in them (about 25-30% of volume), which is not very compressible. So to get 10 grilled cheese sandwiches down to the size of a small cube you’d have to compress them at extremely high pressure where they’d start turning into exotic, high-temperature forms of ice. Most probably to get those 10 down to the size of a small cube, they’d have to be turned into degenerate matter which requires millions of atmospheres of pressure.

So if someone hands you 10 grilled cheeses in the form of a small cube, don’t eat it! 😉