A restaurant server is very busy and has many tables to tend to. Please be considerate of the server’s time as well as the other dining guests by knowing what you would like to order when the server asks. If you aren’t ready to order, simply ask the server to give you a few more minutes.
If you keep the server waiting while you continue to read the menu and hem and haw over each item, they are not able to properly serve other tables, consequently, lowering their overall tip from everyone due to slow or inattentive service.