In many instances you probably won't need menu cards, but there are situations where they may be quite useful:
• Although you may have listed main course options to choose from on the RSVP, if some guests have food allergies, a detailed menu card would inform them of ingredients in the salad and side dishes as well. One or two large menu posters in prominent locations would probably accomplish this goal.
• If you're having a buffet, menu cards would allow guests the opportunity to make their selections before getting in line. This would greatly reduce confusion over what any given item is, and the line could progress more quickly.
• A menu card adds a decorative touch to your place setting, and is an opportunity to continue the look of your wedding theme around each table. You could also include other information on the second side of the card, such as a lovely thank you note to your guests.