Once long time ago , i used to work as waiter , here are my conclusions:
1= People from US , they are quite generous , when it comes to tip. They are great people to talk and serve.
2= People from England : sometime we had to run and catch them to get the money of bill. They eat and try to escape without paying. Some of them are good , but most of them sucks.
3= Pakistani and Indian: They always order the cheap food and act as they have bought the entire place. They always complain why it is so expensive. We never expected tip from them. They never order for drinks or soda , mostly they ask for "water".
4= Arabic = The first thing they ask" If is it Halal ". They fall among those class , who put 99 % efforts to find Halal food and only 1% efforts to make their income Halal. Government funded social losers 😉
5= Danish people : They are best when it comes to tip. Some time they even leave like 500 AED as tip , it always matter to sell them good and s.e.xy wine 😛 ...
6= Eastern european: They hardly have money to come inside . They usually order for one dish and couple of people share it.