You have to book as a Magic Your Way package plan to include or add the Dining Plan. Or be a DVC member. You don't have to buy room tickets for your length of stay, though. You can buy a package and only purchase tickets for the days you need them. The Dining Plan, however, is for the entire length of stay, credits determined by number of nights staying. You would have to price it out to see if it's worth it to book this way.
Last trip: Dolphin, March 2013
Past Stays: Contemporary, Grand Floridian, Polynesian, Beach Club, POP, POR, Dolphin
1990 August Honeymoon - Grand Floridian
Delighted Disney Return Guest since 1981