Tips are given as a gesture of your satisfaction for good service and good meal. You're not subsidizing staff salary. Just showing you are happy at the end of a nice dinner.
Everything has a 21% value-added tax to its price. That's why you won't see anything added to the price tag. In restaurants you pay a tax for seating.
Most dinner clients leave from a few Euros to as much as 10 Euros. About half of the lunchtime clients leave a tip after their meal. You may tip the hotel porter and taxi drivera couple of Euros .
You can decide to extend a tip to your city tour guide, though this is not common.
It's impolite to tip the owner of a restaurant, but you are welcome to leave a token of your appreciation to your waiter.
Most people leave between 5-10 Euros as a tip.
You won't get your dinner bill unless you ask for it. It's called a "conto".