A small band of Jewish students, arms entwined and voices raised in Hebrew song, paid tribute yesterday to slain Achille Lauro hostage Leon Klinghoffer in a peaceful protest in front of the Palestine Information Office in downtown Washington.

The voices of about 30 college students pierced the quiet Sunday afternoon with angry shouts of "PLO -- must go," as the group called on President Reagan to close the Palestinians' office. Then the students switched to muted tones for a memorial service, filled with Hebrew songs of both mourning and hope, for Klinghoffer, the 69-year-old stroke victim who was shot by terrorists and then thrown overboard with his wheelchair during last week's hijacking of the Italian cruise ship.

Rabbi Morris Gordon, who heads Congregation Har Shalom in Potomac, faced a simple wooden casket and a wheelchair adorned with a memorial candle and asked that Klinghoffer's "sacrifice not be in vain."

"May the world take heed that he was murdered by the PLO," Rabbi Gordon said during the sidewalk service in front of 818 18th St. NW. "May the world rid itself of terrorism."

The building, about four blocks from the White House, houses an office that founder Hatem I. Hussaini has said was opened in 1978 to spread the views of the Palestine Liberation Organization. No one could be reached for comment at the office yesterday.

PLO leader Yasser Arafat has publicly disowned the Achille Lauro hijackers. However, U.S. officials have charged that Mohammed Abbas, leader of a Palestine Liberation Front faction closely allied with Arafat, "masterminded" the piracy.

Yesterday, several of the students, who are attending a national Jewish youth conference in Washington, said it was a "disgrace" to allow the PLO to have an office in the city.

"We wanted to make people aware that a terrorist group, which terrorizes Americans throughout the world, has an office right in the middle of Washington," said Martin Nitsun, a 21-year-old University of Indiana student and member of a Zionist youth group. "It is absurd."

During the memorial service, Gordon said, "It's time to throw out the PLO . . . time we were free from organizations which mean terrorism."

Gordon said of Klinghoffer, "His soul and spirit are here. He is here in the nation's capital."

Led by Efraim Sapir, a cantor from Toronto, the group sang the kaddish, the traditional Jewish prayer for the dead. Encircling the casket, and swaying from side to side, the students ended the service by mournfully singing a Hebrew prayer that means, "Let there be peace."