The Chinese manners is differend from other countries .In China, people first meet to shake hands.When people eat,Besides soup, table all food use chopsticks.Certain foods can move chopsticks eyes.And sometimes the Chinese host use their chopsticks to put food in your bowl or plate. This is a sign of politeness. The appropriate thing to do would be to eat the whatever-it-is and say how yummy it is. If you feel uncomfortable with this, you can just say a polite thank you and leave the food there.
Don't tap on your bowl with your chopsticks.Beggars tap on their bowls, so this is not polite.Also, when the food is coming too slow in a restarant, people will tap their bowls. If you are in someone's home,it is like insulting the cook.