Finding a restaurant to accommodate 40-50 people in Las Vegas is surprisingly easy.
The Venetian and Palazzo, for example, have more than a dozen restaurants between them that can accommodate a party as large. So if you have a favorite restaurant here, you should definitely give it a call ahead of time and see if it can work with you; in the meantime, we’re more than happy to recommend a few of our favorites.
For a party spot with good food and a stunning view, you can't do any better than Top of the World at the Stratosphere. The restaurant has four private rooms on the 103rd and 104th floors, each of which can comfortably seat up to 80 people. When you book, you have a choice of ordering from the restaurant's fine-dining menu or from the hotel's catering menu, depending on your taste and budget.
If a party is looking for a celebrity-chef experience, Emeril Lagasse's Delmonico Steakhouse can handle a party of three or four dozen, as can Thomas Keller’s French bistro Bouchon, both located in the Venetian/Palazzo.
That's just a personal shortlist -- there's really no shortage of restaurants willing and able to host larger events. Just be aware that parties of more than 10-12 people are usually required to order from a more limited menu; it's simply too difficult for a kitchen staff to serve several dozen people at the same time if they're all ordering from the house menu.
And be sure to call in advance to reserve your spot and give the staff fair warning, so they can assist in planning a memorable occasion.