I came across these today.
Known as 元蘑 (yuán mó) in Chinese, they are the highly rated "Honey Mushrooms", Armillaria mellea. They have been compressed and dried (or vice versa) into little tablets measuring 2½ x 1½ x ¼ inches. The packaging suggests stewing them with chicken or "meat". They shouldn't be eaten raw as they are slightly poisonous when uncooked.
This block is soaking now, just to the side of my computer desk, and the smell is amazing.