Patience is a virtue in any country. This sign was in the restaurant of the hotel where we stayed during our Tanzania trip. It proved to be true. On the advice of the people we were visiting, they said, "Order your food first. Then take a shower and relax. Come back later for your dinner."
The little red lightbulb was a remnant of a system for waiters to see the progress of their orders (or something like that). I suspect it hadn't been used in years.
The dinner was good. I ate fish curry. Tanga is on the coast, so the fish was fresh.