In our American culture, we often look at dining as the equivalent of filling up at a gas station. Italians think of it as more of an art to take pleasure in. Two-three hours for dinner is considered normal. While there are a few restaurants which try to turn tables twice in an evening, most don't expect to, unless they cater to tourists.
Waiters also wait for someone to ask for the check so they know who to give the bill to. Often, the host at an Italian restaurant excuses himself from the table and handles the bill quietly outside the view of the other guests.
I have an Italian friend who felt insulted at a very high end restaurant in New York (Le Cirque) when the waiter brought the check without either of us having asked for it.

