There are many differences between those two options. First and foremost, in order to add a dining plan to your package you must be staying on Disney property at a Disney owned and operated hotel, whereas you may purchase a Tables in Wonderland card to use at any time for one year from purchase date. The Tables in Wonderland card is a straight 20% discount off of all food and beverages purcahsed, including alcohol, but you pay each time you sit down to eat. The Disney Disney plan is a pre-paid addition to your Disney package, and all that you must pay out of pocket when you use it is alcohol and gratuities. Also keep in mind that the Dining Plan covers more than just table service meals, and in comparison the Tables in Wonderland card only provides a discount for table service restaurants and limited counter service restaurants in the Animal Kingdom. As a local resident and annual passholder I purchased a membership for Tables in Wonderland, but I do recommend the dining plan to my clients staying at the Walt Disney World resort. It truly is based on how much you will be eating on property and what types of food you may want to enjoy.