It wasn't clear what it had to do with U.S. foreign policy, but three Japanese sumo wrestlers in their traditional scanty attire performed a brief ring-entering ceremony in the grand Benjamin Franklin Room at the State Department yesterday. Secretary of State George Shultz was there for the performance, as were about 200 other State Department employes in their pin-striped best, and, for the moment, leaving world affairs to run themselves. One of the wrestlers, Chiyo-no-Fuji, was carrying on a family tradition. His great-grandfather starred 75 years ago before President Theodore Roosevelt . . .

William L. Peterson, who opens at the Kennedy Center Friday in the role of Jack Henry Abbott in Chicago's Wisdom Bridge Theatre production of "In the Belly of the Beast," is also being featured in the June issue of Gentlemen's Quarterly in a fashion spread. Friday's show, taken from the book of the same name by Abbott, the convict befriended by author Norman Mailer, will mark the 150th performance of the play since it opened Sept. 9, 1983 . . .

President Ronald Reagan and Nancy Reagan have become charter members of the Calexico (Calif.) High School antidrug abuse club named in honor of Enrique Camarena Salazar, the Drug Enforcement Administration agent killed in February in Guadalajara, Mexico . . .

Collector Malcolm Forbes has broken another record. He showed up yesterday at Sotheby's auction in New York City and purchased a Faberge' imperial Easter egg for $1,760,000. The previous record was at a Christie's sale in Geneva in 1980 when a Faberge' egg sold for $236,000 . . .

Comedian Milton Berle is doing "just splendidly" a day after undergoing quadruple-bypass heart surgery in Los Angeles. His condition is expected to be upgraded to fair. A Cedars-Sinai Medical Center spokesman said everything is going so well that Berle's son Billy joked "that halfway through the surgery, his father woke up and made suggestions on how to improve the lighting" . . .