Four miles away is Harrison Ave, Exit #287 on I-40. Less than 1/2 mile down Harrison is Bonefish Grill, Ruth's Chris Steak House (yes, $$$ and not always worth it), An Restaurant (http://www.ancuisines.com/), Cafe Carolina, and Moe's Southwest. I think this is the highest concentration of restaurants near the RBC Center. And if I-40 gets too busy coming back to RBC, you can take the back roads: Harrison Ave, left on Reedy Creek Rd, left on Maynard, next left onto NC 54. Go Canes!
2800 Renaissance Park Place, Cary, NC 27513
2060 Renaissance Park Pl, Cary, NC 27513
Moe's Southwest Grill at the Arboretum
127 Weston Pkwy, Cary, NC 27513
Ruth's Chris Steak House
2010 Renaissance Park Place, Cary, NC 27513
Bella Monica really is a great establishment, it is an Italian restaurant in a strip mall on Edwards Mill Rd. I wouldn't call it fancy even though the name implies that it is. If you are looking for a bar there is also Edwards Mill Bar and Grill within the same shopping center. I can't speak for the food though I've never actually eaten there.
I recommend Bella Monica, a tasty, informal Italian place in a shopping center on Edwards Mill not far from the RBC Center. Menus and wine list at http://www.bellamonica.com/
Lots of good salads and pizzas - also heavier entrees but I haven't tried those. But I can't get enough of their arugula salad with grilled chicken.