The Justice Department agreed yesterday to give a House subcommittee most of the documents it is seeking for an investigation of Ronald Reagan's 1980 presidential campaign, including videotapes of Reagan's practice sessions for his televised debate with President Carter.

"The department is going to provide access to large amounts of material, starting, I believe, tomorrow," said James Hamilton, special counsel to the Post Office and Civil Service subcommittee headed by Rep. Donald J. Albosta (D-Mich.).

Hamilton said that Justice officials remain "hesitant" to give the panel certain documents until the FBI completes its own investigation of whether there was criminal wrongdoing in the Reagan campaign's recer White House documents. He said he would keep pressing for that material, which is understood to include summaries of FBI interviews with witnesses.

In another development, House Minority Leader Robert H. Michel (R-Ill.) asked Albosta to investigate whether Carter administration officials worked on the 1980 campaign. A copy of the letter was sent to the Justice Department.

Citing press accounts that and National Security Council aides prepared Carter's briefing papers for the debate, Michel asked: "Were Carter White House staff members or other government employes used to create, compile, research or in any other way work on documents that were used for campaign debate or other partisan political purposes . . . ? "

The letter followed similar remarks by Reagan at his news conference Tuesday. The presidet said: "There could be the element of, were these things actually stolen by someone in the White House? Was there involvement of White House staff in campaign activities who were supposed to be performing other government positions? There are any number of things that should be looked at."

Hamilton, after meeting with Associate Attorney General D. Lowell Jensen, told reporters that "even though every issue was not resolved, it was a positive meeting."

Micah Green, the subcommittee staff director, said the panel will receive all documents the White House has turned over to Justice, which are expected to include results of a brief internal inquiry into the matter by White House counsel Fred F. Fielding.

Green said the panel also will obtain material the FBI has uncovereapes of Reagan's rehearsals for the debate.

As for Justice's insistence that some papers be withheld, Green said, "We're not sure yet how that jibes with the president's offer of access to 'all' documents. But Justice has offered enough documents to keep us busy for a while . . . .

Green said the panel also will receive copies of Reagan campaign documents that FBI agents retrieve from the Hoover Institution at Stanford University after that search is completed, probably next week. The panel still is demanding independent access to those files.