What did Moses do with the stone tablets when he saw the golden calf?

Answer: He shattered them

Seeing the calf and the dancing, Moses burned with anger and threw the tablets down, shattering them at the base of the mountain.

“As Moses approached the camp and saw the calf and the dancing, he burned with anger and threw the tablets out of his hands, shattering them at the base of the mountain.”— Exodus 32:19 (BSB)