More than thinly-sliced beef McNuggets
Arby's carved itself a unique niche with its unusual menu revolving around "roast beef". I put the term in quotations because the material does not resemble any other roast beef-type substance you're likely to encounter. Because it's chopped and formed, it's kind of like a huge beef McNugget. Now, let me make it clear that I point this out not to knock Arby's - in fact, whatever the stuff is, I think it's tasty, particularly slathered with Horsey Sauce. I just like to call a spade a spade.
Arby's menu has long consisted mostly of various iterations of the "roast beef" sandwich - regular, large, Big Montana (a.k.a. more "roast beef" than any single human should consume at one sitting), beef n' cheddar, etcetera. They've also sold a pretty strong fried chicken tender, plus the famous fries (curly or regular). A couple of years back, the Arby's powers-that-be introduced the Market Fresh line of sandwiches.