Tofu is made from curdled soy milk. It has a firm but soft consistency, a little like a soft cheese. Tofu can be used as a meat substitute in many dishes, or cooked on its own. Tofu can be prepared in a huge variety of different ways, just as meat can.
Tuna is a type of large, carnivorous saltwater fish. The tuna in the picture is around 8 feet long. They are a very popular fish for eating. Meat from tuna is commonly sold in cans. Fresh tuna meat is popular in sushi and sashimi, and fresh tuna can be cooked as steaks.
Turmeric is a spice made from the root of a plant related to ginger. It is usually sold dried and powdered. It has a slightly peppery flavor, but is mainly used for its bright yellow color.