According to the Chinese, when someone pours tea into your cup, tea etiquette requires you to lightly tap the table top a few times with your fingers in order to respectfully thank them.
This etiquette is believed to have been passed down from Emperor Qianlong.
One day, Qianlong disguised himself as a commoner, and he had tea at a nearby tea house with his group of advisors.
A waiter first brought a tea bowl, then he stepped back a few steps from the table. He raised a big copper pot and poured water into the tea bowl. All one could see was a stream of water coming down from above directly into the bowl, without splashing or spilling the tea.
Emperor Qianlong was so curious that he could not help but walk up and take the big copper pot from the waiter. The emperor imitated the waiter, took a few steps back and poured water into the rest of the bowls.
His advisors were startled. They wanted to kneel down after receiving such a favor, but they were afraid to expose the emperor’s true identity. Faced with such a dilemma, all of them bent their fingers and started tapping on the table, “tuk tuk tuk…”
Later, Emperor Qianlong asked his advisors: “Why were you tapping on the table with your fingers?”
They said: “Your majesty, we could not have you serving tea to us. We tapped the table to let you know that we were kneeling down to accept such a favor and also to thank you for it.”
Since then, ordinary people have also adopted this custom by tapping on the table to thank someone who serves tea to them.