Janet Reed always buys the best nurse's shoes she can find. As a sandwich maker on the line at the Health, Education and Welfare cafeteria every day from 11 a.m. to 2 p.m., she learned long ago that "if you don't have good shoes, you might as well just rack it up."

But Saturday night, Reed turned in her white cushioned soles for black dance pumps as she and her fellow "ladies on the line" joined a thousand cooks, waitresses, maitre d's, bartenders and housemen at the city's Hotel and Restaurant Employees Union annual Harvest Ball in the Shoreham Hotel.

"Tonight we don't care what kind of meat you want on what type of bread. We're just here to have a good time," Reed said as she tipped her glass to the band.

Usually relegated to an anonymity relieved only by a name tag and the passing of the cream soup, the members of local 25 were clearly out to make an impression. Crystal beads hung from earlobes, from waistbands and from chains that stopped neatly at the cleavage. Blue silk fluttered over mink and blue embroidery shadowed the starched white of John Fennell's tuxedo shirt.

"You have to remember that this is a craft," said Fennell, who spends his days as maitre d' of the six banquet rooms at the Sheraton Carlton. "We are professionals."

Manuel Barona stood at the back of the ballroom, his red jacket and black tie in place, his shoes polished. He was "on" Saturday evening, one of the unlucky ones who had to work.

But he was not complaining. The industry goes easy on its own. "These are my people here tonight, and I want them to have fun," Barona, a 14-year veteran, explained.

"I have to have somebody bad or food that's bad before I ever complain," said Hilda Roth, who works as a banquet waitress at several Washington hotels. "We know what it's like on the other side. How you have to serve a whole dinner to four-star generals in an hour and disappear before the speaker starts. One night, I was serving Marion Barry, and I told him, 'i sure hope I don't drop the soup on you.' That's the nightmare of every waiter, to spill something.

"But tonight the help is on its toes. They have to be; we know what they're doing."