Salad Dressings
More often than not, people put vinaigrette or salad dressings in the refrigerator but research has shown that there is actually no benefit to doing this. The two main components of a salad dressing is vinegar and oil – neither of which requires refrigeration. However if you create your own, you probably use fruit juice, nut oil, or garlic, and those ingredients do require refrigeration.
Salad
If you have an oil or vinegar salad, it is totally capable of withstanding a long period of time not refrigerated. I know, seems crazy. However if you have a salad with a yogurt or mayo base, then you do need to refrigerate.