A mass was offered in Arlington National Cemetery last night in memory of Robert F. Kennedy. It marked the 10th anniversary of the senator's assassination and it was said near his grave and that of his brother, assassinated President John F. Kennedy.

Ethel Kennedy was present. Several of her and Sen. Kennedy's children, including Rory, who was not yet born when herfather was killed, read parts of the service.

Jacqueline Kennedy Onassis also was present with her two children as were Sen. and Mrs. Edward M. Kennedy and several other members of the Kennedy family.

Vice President Mondale was there on behalf of President Carter. Many members of Congress and many former Kennedy associates also attended.

So did about 1,000 members of the public. They stood on a green hillside below the portico of the Custis-Lee mansion next to the small paved area where the Kennedy family and the dignitaries were gathered.

Among these members of the public were W. R. Boggs, his wife Virgie, his daughter and son-in-law, Becky and Randy Barnes, and his grand-daughter, Candy Clippard. The Boggses live in Alexis, N.C., which Boggs described as "just a country crossroads," and the Barneses live in Knoxville.

Boggs said the family was touring Washington and that they had arrived at Arlington National Cemetery much earlier in the day, heard that there was to be a service for Robert Kennedy, and decided to stay.

"We haven't had a bite to eat since 11:30 this morning and we've been so excited we're not even hungry," he said after the service. By then it was almost 8 o'clock.

The mass was offered by the Rev. Gerry Creedon. He was assisted by Msgr. Geno C. Baroni and the Rev. Albert F. Pereira. The service began with the St. Luke's Folk Singers singing "America." The group is made up of 16 youngsters.

Michael Kennedy then read an excerpt from a speech his father gave in Cape Town, South Africa, on June 6, 1966. It said in part:

" . . . The lesson of our time is that all must march toward increasing freedom, toward justice for all, toward a society strong and flexible enough to meet the demands of the future. Let us then give our strength and our sweat, our lives and our labor, and together we will make a hemisphere full of such freedom's sons as will make the earth to sing and tremble in their passing."

The theme of action on behalf of the needy and in the name of freedom and equality was repeated throughout the mass.

"This memorial service is not a question of words, it's a question of deeds," Creedon said.

Creedon also read the Beatitudes: "Blessed are the poor in spirit, for theirs is the kingdom of heaven. . . . Blessed are those who are persecuted for the sake of justice, for theirs is the kingdom of heaven. Rejoice and be glad, for your reward is great in heaven."

Four Robert F. Kennedy fellows also spoke. They were Dale Grundy, who runs a student program in Philadelphia; Dennis Magee, who runs an Indian health program in California; Guido del Prado, of the KBBF Bilingual Broadcasting Foundation in northern California, and Gerald Hildebrand, who works in a proverty program in Mingo County, W. Va

Magee said, "His spirit reaches within and it reaches without and with that spirit we can reach the sun."

When the service was over, Ethel Kennedy and Jacqueline Onassis made brief visits to the Kennedy gravesites, where a flame burns. Three of the younger Kennedy children got into a tie-pulling tussle and rolled on the grass. A fourth Kennedy child broke it up.

At the end, Ethel Kennedy got behind the wheel of her car, Which had several children in it, and drove off.