Hi Carol, In "high season" reservations at least a week before are pretty much mandatory; not so much this time of year. Particularly if you are a large party, it is a good idea that at least some arrive a little before 1:00 to secure the table.
The menu at RDV is eclectic, with something for all tastes: good, thin-crust pizzas, burgers, salads, the tuna tartar, and great-looking desserts, as well.