Night talker Larry King is checking into New York Hospital in Manhattan Sunday and will undergo bypass heart surgery on Tuesday. The 54-year-old Cable News Network and Mutual Broadcasting interviewer suffered a mild heart attack in February and since then has abandoned his three-pack-a-day cigarette habit and radically altered his diet. King said yesterday that his doctor told him he "was going to have to have the operation sooner or later, and that I might as well get it over now while I'm in otherwise good health."

King said he was told it would be three to five weeks before he would be back on the air. His Monday columns in USA Today have been written ahead so they will continue uninterrupted. Hollywood gossip Rona Barrett, who has substituted as host for CNN's "Larry King Live" show, will sit in for him on television during his recovery, broadcasting from Los Angeles. Two substitutes for Mutual's late-night "Larry King Show" will be former CBS reporters Morton Dean and Daniel Schorr, who is now heard over National Public Radio. King, who has just signed a new five-year contract with CNN, will celebrate the 10th anniversary of his radio show Jan. 29. Out and About All that commotion and all those Secret Service agents at the Thai Flavor restaurant on Macomb Street Monday afternoon swirled around presidential candidate Jesse Jackson, who was speaking to a group of about 60 members of the Foreign Correspondents Association before leaving for the Middle East. Jackson's movements attract more public attention than usual nowadays because his entourage has grown to include the Secret Service. So far, he is the only presidential hopeful besides Vice President Bush to be accorded such protection, because of the great number "and precision" of threats made against him ...

Retired Supreme Court chief justice Warren Burger is in London today to give the annual Winston Churchill lecture at the English Speaking Union. As chairman of the Commission on the Bicentennial of the U.S. Constitution, Burger will speak on the Constitution and the British tradition. Previous Churchill lecturers have included former Yale University president Kingman Brewster, the late ambassador Averell Harriman and former president Gerald Ford ... And tomorrow, Washington historian Joan Ridder Challinor will also be speaking on the bicentennial at a Thanksgiving Day service for members and guests of London's American community at St. Paul's Cathedral ...

Tom Pollock, chairman of MCA Motion Picture Group, and Michael Williams-Jones, president of United International Pictures, have issued a formal challenge to the South African government to permit public showing of Sir Richard Attenborough's antiapartheid film, "Cry Freedom." The film is the story of the relationship between Stephen Biko, founder of South Africa's Black Consciousness Movement, and white South African newspaper editor Donald Woods. Biko died in a South African jail in 1977. The challenge stipulates that the movie must be shown unedited and uncensored and be exhibited only in integrated theaters. If those stipulations are met, all of its profits in South Africa will be donated to the UNICEF fund for South Africa ...

You have to be a Republican to get away with some things, or at least Rep. Larry Hopkins must have hoped so when he said the following to the folks back home in Lexington, Ky.: "We've all been reading about the deficit-reduction summit and the proposed $9 {billion} to $12 billion tax increases. We also remember when President Reagan said taxes would be raised over his dead body. Well, if Ronald Reagan had lived, I guess we wouldn't have this problem."