First I would suggest going their on your own. Do some work on a laptop or read a book or something. Give her the opportunity to approach you and gauge how she speaks with you. Then decide if you think it is worth a shot.

Speaking as someone in the restaurant industry, she just might be a really great waitress who is taking care of her section. You and your friend group might be likable and pleasant customers. She appreciates you and your friends as regulars and wants to give you guys good service.

In my experience, they are often the ones to break the customer/server boundary in subtle ways if their interested.

By going alone, you give her the opportunity to break the ice. If she is talkative, asking personal questions, and being approachable. Then maybe ask her out.

Some Tips

Be honest about what your doing there. Don’t just type away at nothing or read a book your not genuine interested in. She would be able to tell if your being strange.

Try to be fashionably well dressed and groomed. It will give her an easy topic to talk to you about.

Make sure whatever it is that you chose to do while dining their alone is something you can easily talk about. Something related to your hobbies, a career goal, or a personal project.

If she turns you down. Be normal, don’t be bitter. Understand that the connect you have is one of service. Continue going their with your friends like nothing happened. That shows that your a good guy and understand the friendly relationship you as a group have.

Maybe she reconsider once she feels comfortable that you were honestly interested and it didn’t bother you at all. It would show that you are a genuinely mature guy who can have a non-romantic friendly relationship.

Best of luck.