I think your best bet for more than a salad would be Tokyo Dining, the sushi restaurant in Japan. They have veggie tempura, edamame, and perhaps they could make you some veggie sushi rolls.
The only other thing I can come up with for a vegan at Epcot isn't a TS. Tangierine Cafe is the Morocco CS and they have falafel, couscous, tabbouleh, hummus, etc.