Yes, the chinese (esp. in big family) can't do that.
It is because, in the past, the poor people who乞食 will wait take a 碗 and wite outside your door and 敲碗敲碟 every night.
Then, those rich people will give them all the food they can't finished (after they have dinner) to them.
When my mother was a little girl, she do that (give good to the poor) everyday............ just like to feed the 'dog'.