Here's a secret: european waiters and restaurant owners know USA tourists are accustomed to tipping and will have no qualms making those tourists believe tipping is customary. I saw this happen in an Italian restaurant when the propietar believed her customers to be from the USA, she took the cash money and didn't even bother bringing their change since she assumed they had added it as their tip.
As someone who both grew up and lived his whole life in Europe, I assure you that tipping is exceedingly rare and most certainly never expected nor customary, even in restaurants.