You can use an egg slicer to slice more than eggs. It does a great job on all sorts of foods, like strawberries or mushrooms.
Note: Do not use a “cheap” egg slicer to slice mushrooms. I have broken a couple of egg slicers this way. Invest in a good one. Here is an updated version of the one I own. It is dishwasher safe, sports an aluminum frame and stainless steel wires and is only about $7.50!