Tawnni grew up in Oregon and was a cheerleader at Central High School. Following high school graduation, Cable briefly worked as an agency fashion model in New York City. She was chosen as Playboy's Playmate of the Month for June, 1989. Her centerfold was photographed by Stephen Wayda. She went on to pose for a bunch of Playboy special edition publications and was featured in many Playboy videos.
She played a small role in an episode of The Fresh Prince of Bel-Air as a cardiac surgeon/Playmate whom Wil unsuccessfully hits on. She also appeared with four other Playmates on an all-star episode of Family Feud, where in one episode she was a part of an infamous blooper where when leaning over to give Young and the Restless star Kristoff St. John a kiss for giving her a rose, her breasts set off the buzzer on the face-off podium.
An avid lover of the beach, sun and surfing, Tawnni Cable eventually moved to Hawaii where she still lives to this very day.