Vig Deli is (thanks to the change in operating hours of The Red Cup Cafe) the only place to get food 24 hours a day at The M Resort.
The menu features a wide array of different Burgers, sandwiches, salads and so on. Serving sizes are large and well presented and the prices are affordable.
Unfortunately this is very much "fast food" - the stuff looks MUCH better than it tastes and the eating area is rather small and soul-less like a food court. If you are at M late at night and find yourself the victim of a snack attack - this will do just fine. Otherwise it's not something to go out of your way for.