Yes, you can buy any of the three dining plans, quick service, regular or deluxe. The Premium and Platinum Package Plans (the ones that include tours and recreation as well as dining) are not available on DVC reservations.
If you are a DVC member or trading in you must call Member Services to add a dining plan no later than 48 hours before your arrival date. If you are renting points from a DVC member, you must have the DVC member call Member Services and add the plan. You must pay for the plan when you add it.
Everyone registered in the room age 3 and over must be on the same dining plan, and you must purchase it for the full stay.