What do you do with a kid like that?

Gene Williams is 8 years old, and has been a professional actor since he was 4. This week he begins four weeks filming for the soap opera "Search for Tomorrow," knowing only that he will play a sick boy in a hospital. It will be time enough to see the script a few hours before filming, he says - he has an excellent memory.

According to him and to his father, Eugene Williams, who is a professor of education at Howard University - and who says his wife would have been there to testify to the same things if she hadn't been busy teaching - Gene performs the following feats:

He practices half an hour of piano, half an hour of tap dancing and an hour of violin every day without being nagged.

He does his homework first thing when he gets home, and has a fine academic record.

He studies drama in Columbia, Md., where the family lives, and tours with the "Young Columbians."

He goes to education conferences with his parents and listens attentively to the lectures.

he doesn't need an allowance or expect to spend any of the money he has earned from television commercials because all he wants to buy are books and football cards.

He plays footballs, soccer, baseball and softball well.

He watches television news with his parents and discusses it afterwards, but is generally bored by television. He likes to read books instead - "The Prince and the Pauper," "Huckleberry Finn," "Tom Sawyer."

He accepts it if his parents won't let him do a role because it is improper or demeaning, in their opinion; and if he is turned down for a part, he feels "grateful that ar least they let me audition."

And what does this child want to be when he grows up? "Paul Robeson," he said. "An actor and athlete, an inellectual, maybe a lawyer,"

Williams' career started when his parents' tax consultant was visiting and he, as a 3-year-old, picked up some of the tax material and began reading it. Apparently, he read it with feeling, because the tax man recommended him to another client, and advertising agency.

At age 4, he did his first commercial, for Safeway. Then on to Jello (with Bill Cosby). Scope, Kentucky Fried CHicken, Johnson's baby products - he can't remember them all. He does them in a one-day trip to New York, or during the summer, so he doesn't miss school.

Last year he made a film, "The Man WHo Loved the Stars," with Ossie Davis.

And what has all this made of the child?

Well, as his father says, he is well-mannered, animated, interesting and attractive. His redeeming quality is that he fidgets while he's being interviewed.