Senate Minority Leader Bob Dole has kept his staff busy finding those daily congressional "Bicentennial Minutes" that he enters into the Congressional Record. Yesterday he pointed out that 57 years ago on that date, his colleagues were waging an all-out war against dial telephones in favor of the operator-assisted kind. That's the kind of issue the Senate can sink its teeth into. Though the phones had been invented decades earlier, senators didn't like them much; President Herbert Hoover even banned them from the White House when he took office in 1929.

The Senate did adopt a resolution offered by Virginia's Sen. Carter Glass that the dial telephones be taken out on the Senate side. Lobbyists for the telephone company worked hard to get that reversed and, true to the way things happen on the Hill, won a compromise permitting members to choose the type of instrument they wanted. It seemed that no senator wanted to place his own call. There are people on Capitol Hill who will tell you that nothing has changed: No senator there ever places his own telephone call. RFK Files to Be Released Nineteen years after the assassination of Robert F. Kennedy, the Los Angeles Police Department's investigative files on the case are about to be released. Ever since Washington investigative reporter Dan Moldea's article "Who Killed Bobby Kennedy?" was published in the June issue of Regardie's magazine, interest in the murder case has had a resurgence.

Moldea said yesterday that he expects to see the case reopened after all these years. He contends there was another gunman involved and that the Los Angeles Police Department botched the case. About 50,000 documents are to be released, and California archivist Chuck Wilson, noting the increased public interest in the material, said that "every effort will be made to make it available as soon as possible." Out and About Fred Astaire, who so tightly guarded his privacy he did not want his children at his bedside when he died Tuesday, was buried quietly Wednesday in Los Angeles alongside his sister Adele and his first wife Phyllis Potter, according to a spokesman. Two clergymen offered prayers at the burial, but at Astaire's request there were no eulogies. Only his second wife, former jockey Robyn Smith, 42, his son Fred, 50, his daughter Ava, 44, her husband Richard McKenzie and a close friend, choreographer Hermes Pan, were present ...

Vice President George Bush and his wife Barbara showed up at the Palm restaurant Wednesday evening to dine with friends and brought their usual contingent of some 20 Secret Service agents, who were everywhere -- at a table, in the kitchen, outside and in the garage. And with all that protection, no one walked over to his table to get an autograph ...

A two-day international symposium on political humor opened in Philadelphia yesterday with such well-known funny men as Mark Russell, Dick Gregory, Art Buchwald and Andy Rooney. It brought together entertainers, writers and cartoonists from 25 countries, including the Soviet Union. Russell pointed out that the symposium was in Philadelphia on the 200th anniversary of the Constitution, and that "we are here honoring the Constitution, an ingenious document which grew to protect Nazis, the Ku Klux Klan, Larry Flynt, Oliver North and the entire computer dating division of the PTL Club." And, he added, for all the trouble humorists cause in the United States, "there are more politicians in prison than there are humorists" ...

Andrew Lloyd Webber, who has brought such London theater hits as "Cats," "Evita" and "Starlight Express" to Broadway, is having problems trying to bring "The Phantom of the Opera" to New York with his wife Sarah Brightman in a starring role. Actors Equity wants an American to play the lead female role because American actors need the work and there is an exchange agreement. Webber, angry about the decision, is threatening to keep the show, which is now scheduled to open Nov. 12 and expected to be a big hit, off Broadway altogether. To add to the situation, Steven Spielberg has offered to make a movie of the show if Webber choses to bypass Broadway. Some compromise is likely soon, since Broadway needs "Phantom" ...

Sen. Alan Simpson, one of the few genuine wits on Capitol Hill, said he walked by the Iran-contra hearings and saw a sign that read: "The buck doesn't even slow down here" ...