Cut tops off tomatoes. Gently squeeze out seeds and discard. Scoop out the flesh using a melon baller or spoon and reserve 1 cup; chop and set aside. Place tomatoes cut-side down on a paper-towel-lined plate; allow to drain.
Stir together reserved tomato, surimi, yellow pepper, mayonnaise, onion, sour cream, lemon juice, cilantro, salt and pepper in a medium-size bowl.
Fill tomatoes with a heaping 2/3 cup of crab filling, mounding slightly.
Place salad greens in a bowl; drizzle with olive oil and vinegar and toss to combine. Serve alongside the tomatoes.
