Every race track community is full of people who harbor dreams of breaking into the business in a grand way. There are ushers who want to own horses; busboys who want to be trainers; parking lot attendants who want to be jockeys.

Yet rarely has a track employe pursued his ambitions with the diligence of young Bobby Triola. And rarely have anyone's dreams come true so dramatically.

Triola was still a teen-ager when he went to work as a waiter in the dining rooms of the New York Racing Association tracks, where his father was the maitre d'. It was perhaps a good thing that he had such a benevolent superior, for Triola was more enthusiastic about talking and swapping tips with the owners and trainers in the dining room than he was about serving up orders of corned beef and cabbage.

One of his frequent customers was Lucien Laurin, the feisty little man who had trained Secretariat and Riva Ridge. Laurin was a good friend of Triola's father, and he listened patiently when the waiter told him his aspirations. Knowing that the city-bred kid had never had even the passing exposure to horses that rural youngsters do, Laurin told Triola that he had a lot to learn. He offered him a challenge and an opportunity, and invited him to move to the Laurin farm in South Carolina. He added: "There's no way you're going to last."

Since he had reached the zenith of his profession by training the greatest thoroughbred of all time, Laurin had become semiretired, something of a gentleman horseman. He spent much of his time on his farm in Holly Hill, S.C., where he bred and raised thoroughbreds. But if this was Laurin's idea of paradise, it seemed like an alien world to Triola when he left his job as a waiter and moved there.

"I'd been living in Queens," Triola said, "and all that fresh air and stuff was a novelty for a little while. But the town was nothing. I'm amazed I lasted six months on the farm."

If there wasn't much opportunity for recreation in Holly Hill, Triola was kept busy with the intensive education that Laurin had promised. He started the way any common groom would, learning how to clean out stalls. Thereafter, Triola said, "He kind of led me in steps. He wouldn't tell me things more than once, and if I didn't do something right he'd jump up and down and say, 'If you're going to make it you've got to listen!' After about a year he started giving me some authority and gave me a chance to make decisions."

Triola spent more than three years on the farm before Laurin decided he was ready to venture forth--albeit on a very short leash. In the fall he came to Florida, got his trainer's license and started training horses for Laurin at Calder Race Course. His mentor, who has a winter home here, was looking over his shoulder frequently. But Triola proved his three years of intensive education had been well-spent. He won with the first four horses he saddled at Calder Race Course, one of whom was Stage Reviewer, who has proved to be an animal of considerable talent.

"He's phenomenal," Triola said of the 3-year-old, and if that assessment is slightly hyperbolic, Stage Reviewer did look very good winning four of his first six career starts. He earned a berth in the Flamingo Stakes at Hialeah last week, but he had a rough trip in the 17-horse field and finished out of the money. Still, his overall form and his pedigree suggest that he may yet be good enough to run in the Triple Crown races.

If that should happen, both the veteran horseman and his young protege could fulfill dreams of their own. Laurin could return to the scene of his greatest triumphs with a horse he himself had bred and raised. And Triola could return to Belmont Park to watch a race from the clubhouse dining room without anyone asking the whereabouts of his corned beef and cabbage.