Other forms: olios
An olio is a hodgepodge of various things. The contents of your desk might be an olio of books and notebooks, uneaten snacks, the mini flashlight you found on the sidewalk, a golf ball, toothbrush and toothpaste, a Frisbee...
An olio was originally, and still is, a Spanish or Latin American stew containing a variety of ingredients, such as sausage, perhaps other meats, tomatoes, chickpeas, and various other vegetables. The full name for this stew is olla podrida. The word olio came to be used for any collection of many kinds of different things, especially things that don't really seem to belong together or have anything in common. It can also describe a musical medley or a variety show.