It only took eight years and a bachelor's degree, but Leah Beach has finally stopped hearing her least-favorite question: What do you really plan to do for a living?

Ms. Beach is already doing it, as a server at restaurant L20 in Chicago. She meticulously assembles and arranges place settings for the restaurant's 14-course $210 tasting menu. She learns about foods and dishes like velvet crab, matsutake mushrooms and craquelin bread and curates it all into engaging talking points for each new party of guests. "I'm not just listing off a series of ingredients," says Ms. Beach, 31, who moved to Chicago from Minneapolis in 2011 to pursue her food career. "I'm telling them a bit of a story."

Far from biding time before the next acting audition, many of the newest generation of servers at the nation's top restaurants are waiting tables as a way to hone their chops for a career in restaurant management. They are coming out of top culinary and Ivy League schools, and they consider themselves professionals. To get a foot in the door at legendary establishments, many food-obsessed 20-somethings are busing tables.

High-end restaurants are boosting their service game as prices rise up over $100 for a fine meal and guests become more demanding. A sharp wait staff establishes trust before the food arrives. Josiah Citrin, chef owner of Melisse, a Santa Monica, Calif., French restaurant that offers a $125 prix fixe dinner, only wants to hire servers with a professional track record. "When waiting tables, there's no chance to fix the error" Mr. Citrin says. "It's not like in the kitchen."

The kitchen has been the customary entry point for the restaurant industry, with culinary and hospitality grads launching their careers in jobs as prep cooks or line cooks. But recently, ambitious grads are realizing they can earn more money working in the dining room.