In that case, I would assume it was related to "tossed salad". That is where you put salad ingredients in a bowl, add salad dressing and then "toss" the salad to ensure that all the foods are coated with the dressing. You toss it by moving the bowl around in such a way that the ingredients sort of jump up and down in the bowl and get moved around to mix in evenly. Alternatively, you move the leaves and the other ingredients round using spoons or salad servers. The main aim is to make sure that the salad dressing is evenly spread over the salad.