What should you never say to a customer?

"Are you still working on that?"
"Is it just for one?"
"Let me get your server"
"Will you need change"

Dont ask are you still working on that. It is impolite and there are better ways to find out if they are finished. You can ask how is everything so far or ask if they would like any extra noodles. Once they say Oh, no thank you. Im too full for another bowl of noodle. That is the cue where you can ask if you can take it out of the way. Also saying let me get your server means that you are not wanting to take care of them. Remember everyone is your customer even if it is not your table.