A person with a bird can accurately calculate your surname, your future, marriage and so on. What's going on here?

It's simple. Use exclusion. In fact, if you count from each piece of paper, you can only cover one surname. As for what it is, the stall owner certainly knows it by heart. All he has to do is put a small grain of rice, a bug or something in your unguarded situation, suggesting that the bird will naturally take out your last name. This is all a deceptive trick.