PEOPLE WILL TALK. By John Kobal. Knopf. 728 pp. $25.

FILM HISTORIAN John Kobal's 728-page binge for movie buffs, People Will Talk, is a triple hitter, functioning equally wonderfully as an interview book, as intimate memoir, and as a complete history of women on the screen from its beginnings to the advent of television. At times, the book seems to be bursting at its seams with sass and enthusiasm, but it's all of a piece. And its scope provides the reader with nothing less than the Gone With the Wind of Hollywood interview books.

The interviews with 43 women stars and the behind-the-scenes craftsmen who provided the on-screen magic are both peppery and resonant. There are a few clunkers, however. The general rule here is the bigger the star, the less satisfying the interview. Kobal's motor runs a little too fast with Mae West, Katharine Hepburn, Joan Crawford and Ingrid Bergman: he obviously knows more about the backgrounds of the stars' movies than they do; consequently -- and amusingly -- his side of the conversation is much more interesting. And many of these ladies have done so many interviews over the years that they've learned how to phone it in.

The big stars truck out their favorite -- and familiar -- anecdotes and work at being charming, but it's not enough. Probably sensing this, Kobal covers himself with his marvelous introductions to each interview, reminiscing about his visits with the stars and providing for each subject a career retrospective which bristles with critical insight. He calls Miriam Hopkins "the busiest actress ever to cavort before the cameras; the blonde Southern belle who could chase molasses up a tree. She had an antebellum voice and a cash-and-carry mind." Garbo's voice was "like a tugboat; Mae West's, like a vibrating bed; Davis, like a hedgeclipper." Ida Lupino "was more American than the hash she slung."

The actual interviews speak for themselves, and the stars, like kids, say the darndest things:

"Give me a wig and a lamb bone and I'll play Henry the Eighth" -- Gloria Swanson.

"He kept taking his paper hat, making little spitballs, dunking them in his glass of water and throwing them around the room so they landed on the women's bosoms. It seemed so childish to me. The man was Howard Hughes." -- Eleanor Powell.

"I tried to do a little better and find myself doing an imitation of Edie Adams doing an imitation of me." -- Marilyn Monroe.

"My whole point was my vitality, which, if I showed it in pictures, looked as if I had St. Vitus' dance." -- Tallulah Bankhead.

WHILE some subjects are not forthcoming (Irene Dunne, Anna Sten), others are surprisingly candid. Loretta Young readily admits that she had director Jules Dassin fired from one of her pictures, and when asked if she missed the studio system, she replies, "No, because I left it before it left me." The older stars, who started in the silents -- Coleen Moore, Dorothy Gish, Dagmar Godowsky, etc. -- talk about the old days and their lives with a detached air, as if it all had happened to someone else. Evelyn Brent ("the Queen of the Underworld") is characteristically unsentimental: "I was married . . . I have to think . . . three times. The last one was the best one, but he died in 1959."

The only stars interviewed whose articulateness and expressiveness really live up to the fluidity and intuitiveness we associate with screen greatness are Louise Brooks and Tallulah Bankhead. Brooks on Garbo: "You can see that along with her actions is this wonderful mysterious thought line moving below, but it's harmonious, she's at one with her thoughts." Bankhead: "I don't mind shocking people, because to shock them doesn't necessarily mean that you offend them." And when Kobal interrupts the interviews with diary-like anecdotes of the intimate friendships that developed between the interviewer and his subjects, he brings these luminaries back to the once hard-drinking Brooks, he writes, "I wasn't comfortable with drunks. They saw thrhrough you, or they clung too tight." When Bankhead reluctantly gave up smoking, she still encouraged others to light up. "But would you mind, dahling . . . blowing your exhaust my way?"

The very best interviews are with so-called "women's directors" such as Vincent Sherman and the great Hollywood portrait photographers such as John Engstead. The gloves are off here, but the insights aren't harsh; they're pin-point sharp, even poetic. Engstead remembers at age 17 seeing Clara Bow for the first time: "And Clara came in with her little socks and her little high-heeled shoes and her short, short silk dress, tied-around sort of thing, and she was wild, just flying around -- she was just happiness personified."

Throughout, the memories -- sometimes bitter, sometimes self-serving -- are always tempered by the melancholy realization that the old Hollywood is gone and it's not coming back. Louise Brooks' favorite line from Proust becomes a recurring theme: "The only paradise is paradise lost." And that's what Hollywood legends have to hold on to.