Maryland Lt. Gov. Blair Lee III, serving as acting governor for two hours today in place of an ailing Gov. Marvin Mandel, signed into law 53 minor bills and granted Easter commutations to 280 state prisoners.

He then "wasted the last half" of his administration "yakking on the phone," Lee joked as he concluded his fleeting moment of power.

Lee, Senate President Steny H. Hoyer and House Speaker John Hanson Briscoe then conducted the ritual commenatary that always floows the midnight adjournment of the General Assembly. All agreed, in Lee's words, that the session that ended Monday was "disagreeable but responsible."

"When you are dealing with problems to one likes, such as taxes, prisons and the death penalty," the solutions are not likely to be popular, Lee said.

Hoyer and Briscoe agreed that the biggest disappointement was the last-night failure of a bill that would have extended the so-called "circuit breaker" property tax relief to all low and moderate-income homeowners. Exisitng legislation applies only to disabled and elderly homeowners.

"Some (senators) just didn't understand the program," said Hoyer in trying to explain the motivation for a threatened filibuster last night that killed the proposal.

The lieutenant governor wasn't upset about defeat of the circuit breaker, however, saying he found the "funding fuzzy."

The estimated $17 million cost of the program, which would not have gone into effect until July 1, 1978, was to have been covered by anticipated increases in revenue from the state lottery.

Along with the rejection of a $12 million-plus state aid-to-education bill, another victim of a filibuster, "we saved $30 million" in expenses, Lee said.

The education proposal, however, may not result in a saving to taxpayers, however, as local school districts were counting on the money, and some may have to ask county governments to increase the property tax rate to offset the loss of state money.

In Montgomery County, where County Executive James P. Gleason's budget recommending no tax increase is now being considered by the County Council, the defeat of the education aid bill will have little effect, said Gleason aide Charles Maier.

But in Prince George's County, the loss of some $2 million in additional aid has sent the county government scrambling.

County Executive Winfield M. Kelly Jr. also presented his County Council a budget that recommends no property tax increase. But his proposal anticipated $3.5 million in additional state aid. "Even if we had gotten the bill, we would have been $1.5 million short," said Royal Hart, Kelly's lobbyist here.

This session, the General Assembly enacted a law giving Prince George's the power to levy taxes on anything not taxed by the state or forbidden in the county charter. This is the "omnibus tax" or nuisance tax authority that most chartered counties in Maryland already exercise.

The county plans to earn some $5 million from the tax this coming fiscal year by imposing a 15 per cent telephone usage tax.

"The last couple of weeks we got a feeling it (the additional aid to education) wouldn't come through," said Kelly. "The omnibus tax kind of offsets our disappointment but now it's certainly going to be a problem."

With Mandel in the hospital during the final week of the Assembly session, the task of sheperding the adminstration's program through the legislature fell largely on Lee, who observed today that "everything in the administration package that counted got through."

The key proposals were increasing the state's sales tax from 4 per cent to 5 per cent, which will produce an additional $147 million in the 13 months beginning June 1, and the capital budget with its $26 million appropriation for the prison on a site opposed by neighborhood groups and owned by a politically connected developer.

The session closed on one of the most dramatic notes of its entire 90 days, as Senate President Steny H. Hoyer ignored the usual prerogatives of several senators to rush the capital construction budget - including the bitterly disputed Baltimore prison - to passage in the final seconds before the midnight close of the legislative year.

Because of a combination of clerical errors and last-second strategy, the $89 mollion capital budget came up for a final vote in the Senate with so few minutes remaining before midnight that four senators who had filibustered against the prison could have run out the clock and ensured the death of the bill if they had been given the normal two minutes each to explain their votes.

One question Mandel or Lee will have to decide is which of two bills dealing with telephone calls to information operators will become law. A House version, sponsored by Del. Raymond E. Dypski (D-Baltimore) would prohibit the Chesapeake & Potomac Telephone Co. from charging for any call to 411, while a Senate version, squeezed through the House shortly before midnight over Dypski's protests, would give residental users up to 12 free calls a month to information.

The measure on which Briscoe said he received "by far the largest amount of mail" during the session, a bill that would have permitted physicians to prescribe the drug Luetrile, or Amygadlin, died in the last night frenzy when the two houses could not agree on a single version of the proposal. Hundreds of persons, many of them saying they had taken the controversial, unapproved drug as a treatment for cancer, had testified in behalf of the legislation.