Some personal observations..
Q: How does a server know that you are ready to order?
A: If the menu is closed.
Most of good restaurants have thick menus with fancy foreign named dishes. When server comes, one has to open menu again and spend time looking for his/her choice ..again.
Italian restaurants ordinarily serve lots of bread and oil, before main dish is ordered. By the time waiter arrives, people are not as hungry, thus they tend to order less than they originally planned before the bread.