I Use mine as a hotplate! For ThanksGiving I did not have enough pot holders for the table, so I grabbed the Tiles which are 12" and laid them side by side on the table 2 across and 4 down and put all the food on them.
If you have the same model of tiles somewhere in the house, you should keep the extra ones because you don't know when you may need them to replace one. If you don't need them, just sell them. Someone will need them.
Get creative! Use them to line an old kitchen shelf, make a set of divets, use them to paint on with your kids/grandkids, or break them up for a mosaic.