Paper-thin sheets of pressed tofu sold in stacks, pliable and slightly chewy. They are cut into noodle-like strips, tied into knots for braising or rolled around fillings. At hot pot, 百叶 usually means beef tripe.
Beancurd sheets can be eaten rolled around shredded pork.
Tips
culture
千张 (lit. 'a thousand sheets') is a thin, pressed form of tofu common in Jiangsu and Zhejiang cuisine. It is chewier than regular tofu and absorbs sauces well.