Eleven Iranians charged with terrorist activities are appearing before a rare public tribunal in a move that critics of the Shah say is intended largely to blunt foreign accusations of human rights violations by the government.

The 11 - most of them college graduates - pleaded guilty at the opening of their trial here yesterday. The military tribunal now is hearing testimony on the defendants' backgrounds and the gravity of their offenses before sentencing them.

Critics of the government have called it a "show trial" and predict that, although the prosecution has asked for life sentences, the court will give them relatively lenient sentences to mollify foreign charges of repression in Iran and to preempt any U.S. accusations of human rights violations.

So far, in his campaign to defend human rights throughout the world, President Carter has not mentioned Iran.

Court-selected defense lawyers argued that the defendants were exposed to "bad influences" while studying abroad and had become "psychologically insecure" as a result.

The eleven have pleaded guilty to charges of subversive activities. The military prosecutor alleged that the defendants tried to undermine the security of the state. The defense has not answered that charge but has based its case on pleas of leniency.

Iranian Prime Minister Amir Abbas Hoveyda denied that the trial was in response to the Carter policy, but confirmed that foreign public opinion was a consideration in opening the proceedings to the public.

He also indicated that the accused would be eligible for parole after a few years.

The trial affords a rare glimpse into the backgrounds of the accused terrorists and the definition Iran applies to subversivsive activities.

The 11 are accused essentially of associating with the revoluntary wing of Iran's outlawed Tudeh Communist Party, and face life imprisonment under the state security law. No violent terrorist action are alleged, although two of the defendants - both 40, holders of bachelor degrees in agriculture and executive in farming ventures - are accused of having undergone "ideology, sabotage and guerrilla warfare" training in China and Cuba.

The only actual gunplay charged, against two defendents, is target practice in a Tehran Brick factory. Basically the defendants are accused of association with alleged Communists and subversives, mostly while they were studying or living abroad.

According to the prosecution, the accused were linked with eight alleged terrorists who were killed in a shootout with security agents last Christmas Day. Prime Minister Hoveyda also cited association with guerrillas who unsuccessfully tried to kidnap American Ambassador Douglas MacArthur in 1970.

Among the defendants are a 29-year-old university lecturer who holds a doctoral degree in political science; a computer engineer, 36, holder of a bachelor degree in electronics; a university tutor, 31, who holds a master's degree in mathematics; the managing director of a Tehran engineering company, 28, holder of an electrical engineering degree; a 30-year-old woman with a master's degree in accounting, who works as a credit expert at a Tehran Bank; a 36-year-old accountant in a local management firm; a housing ministry employee, 32, with a bachelor of science degree in economics; a 27-year-old architectural student and an electrician.

Usually few such details are given about accused terrorists. The Iranian press has also given the trial unusual publicity.

The defense, arguing that the defendants repented their "deviation," has pleaded for reduced prison sentences to mark the anniversary of the "miraculous escape" of Shah Mohammed Reza Pahlevi from an assassination attempt 12 years ago today.