We are having one at each place setting, because we are having a choice of meal options for each course. If it was alternative drop, we'd probably have 1 or 2 menus in the middle instead.
This is smart - if people actually need the menu to chose their meal, I would provide one per person. If it is just for information sakes, then I think 1 or 2 per table is fine.
We have 3 options per course that people can chose from, so we will be doing one per person, probably tucked into their napkin so it doesn't make the table too "busy".