What is a device used to slice tomatoes with in one motion called? I worked at a restaurant for a month once and they had a device there. It was a rectangular box: you'd put a tomato in it, and there was a handle at the one end you could use to push the tomato against some blades. The tomato would come out the other end in 5 slices.  

It was so much more efficient than using a knife, but I don't know what it was called.

I almost want to say it was a tomato slicer, but I never heard anyone call it that.
Yes, believe it or not... it's called a Tomato Slicer, but they are also sometimes referred to as a Tomato Saber. Which is a product name originally from the commercial company Price Castle.  

Although I agree with Stephie and janeylicious just include the additional keyword 'commercial' with your search.

Another option is that you can try the keyword 'Tomato Saber', this should also aid to a successful search.