When dining out in a foreign restaurant, be sure you understand the accepted etiquette for behavior, tipping, and treatment of the wait staff. Many guidebooks will help you out with tips, but it's better to have someone with you with a thorough understanding of the culture.
If you're dining in a restaurant without reserved seating, it's within your rights to ask for another table it you don't like the one you're shown to. It's not necessary to make a fuss, however, and keep in mind that they may not be able to accommodate you if they're busy.