The Senate Judiciary Committee approved yesterday the nomination of Assistant U.S. Attorney Royce C. Lamberth to a federal judgeship here, but Sen. Edward M. Kennedy (D-Mass.) blasted the Reagan administration for nominating 14 white men consecutively to the federal bench in the District of Columbia since 1981.

Kennedy emphasized that he is not opposed to Lamberth, whose nomination was approved by voice vote. But he said the full Senate should not confirm Lamberth until the Judiciary Committee holds a hearing on the Justice Department's judicial selection procedures.

"The Reagan administration's apparent attempt to 'homogenize' the federal bench is simply inexcusable," Kennedy said. "Of the 45,000 lawyers in Washington, over 8,000 are women, and more than 3,000 are black or Hispanic. No city in the country has more women and minority partners in its major law firms, or in government service."

Nevertheless, Kennedy said, "Every single one of the 14 persons this administration has nominated to the federal bench in Washington is a white male." Under President Jimmy Carter, he said, three blacks and four women were among the nine nominees to federal court vacancies here.

Spokesman Patrick Korten said the Justice Department "welcomes congressional oversight of our judicial selection process. We believe we have established a superb record of selecting highly qualified individuals to sit on the federal bench."

"It seems to me the tactics are off base," said Mark Goodin, spokesman for ranking GOP Sen. Strom Thurmond (S.C.). "It seems manifestly unfair to hold up a particular nominee, who you say you have no problem with, and use that individual in a political hostage situation."

Committee Chairman Joseph R. Biden Jr. (D-Del.) and Sen. Patrick J. Leahy (D-Vt.) indicated they would schedule a hearing on judicial selection in the next few weeks.

Lamberth, 43, a Texas native who lives in Alexandria, joined the U.S. attorney's office here in 1974 and has been head of its civil division since 1978. He is a career civil servant who headed the negotiations over the District's prison overcrowding problems, and his nomination had been expected to sail through without difficulty.

Paul L. Friedman, then president of the D.C. Bar Association, sharply criticized the administration's judicial appointments at a Senate committee hearing in April.

"The point is that the president has nominated no women, no blacks and no Hispanics in a city whose population is 70 percent black," Friedman said.

Kennedy cited recent Senate testimony by Attorney General Edwin Meese III that Republican senators, who make recommendations for district court nominees in their states, have put forth few minority candidates for the bench.

"The statistics from the District show that Mr. Meese's lame excuse simply doesn't hold water," Kennedy said.

"The District has no senators. No one but the president and the attorney general is responsible for this administration's pitiful performance on judicial nominations."