This is a very nice find. Here in Arizona we call something like this a "metate" and the smaller, hand held grinding stone a "mano". These were used for grinding up food, such as corn, for making flour. They had other uses as well, but mainly for making flour for bread or bread-like food. They are pretty common out west but you dont seem to see as many from back east. This is a nice example for an eastern metate.
