"I travel a lot," said Jimmy Carter, arriving late at a major Democratic fund-raiser last night. "And I know you do, too. And people are interested in inflation. I've been watching it from the perspective of Washington. Here you can get a good meal, be entertained, for only $1,000."

President Carter had his day-a SALT II agreement with the Russians and Senate approval of his gasratioining plan.

He also had a fairly good evening last night, as he stopped by the Democratic Congressional fund-raising at the Washington Hilton entering to a standing ovation and leaving with a leisurely walk through part of the crowd. The Democrats reached for his hand and snapped photos of the ebullient president, and neither he nor the fans halted for the dinner's final benediction.

Yet, in between his warm welcome and his folksy departure, the president's jokes about Robert Strauss, inflation and the Congress, and his cut-and-dried remarks about gas rationing, peace and the general progress of the Democratic Party under his leadership were received with only modest enthusiasm.

"No commitment is more real than out commitment to peace," said Carter. "We have spoken out for human right." Here the crowd of more than 1,500 Democratic contributors and politicians applauded loudly.

But the congressmen who had listened politely were reserving their final verdict on the SALT II agreement. While no one was celebrating, no one was shortchanging its importance either.

"I have to see it," said Sen. Thomas Eagleton of Missouri. "I'm not convinced, but I'm not unconvinced. It will be a tough fight especially on the verification issues."

Labor Secretary Ray Marshall commented, "I'm pleased because I think it's important to have the treaty finalized." He said he thought the chances of Senate approval were "hopeful."

Echoing public dissatisfaction with recent developments in the gas crisis, Ohio's Sen. Howard Metzenbaum said Carter's rationing plan wasn't necessarily the answer, but: "Better to have the government rationing gas-right now the oil companies are rationing it." On SALT he predicted. "A tough road. I'm totally undecided." He said the senators would be taking a long, hard look at verification.

George McGovern (S.D.), one of several senators who attended a White House briefing on the SALT II agreement yesterday afternoon, said, "President Carter was very impressive. But what worries me is not the treaty but the ratification process. I'm going to hold out until the end. I'll withhold my vote."

Sen. Joseph Biden (Del.) echoed McGovern, saying, "We need a couple of things worked out on verification, but i'm going to work for it."

Frank Moore, who will stage Carter's legislative strategy for passage, called SALT "a matter of education for Congress and the public. I wouldn't say we got any converts today at the White House, but it was a good meeting" between Carter and his invited congressional quests.

Inside the mammoth Hilton ballroom where the stage was decorated with a sign proclaiming "The Democrats Are Having a Party," the Peter Duchin Orchestra played quasi disco. Al Ullma of Oregon, chairman of the House Ways and Means Committee, was one of the first out on the dance floor.Tablehopping were Chip Carter, Vice President Walter Mondale and Sen. Robert Byrd, his carefully coiffed pompadour intact.

When Massahusetts Sen. Edward M. Kennedy arrived at the reception, he mingled around the fringes of the crowd, drawing the cameras of some of the fund-raiser's staff, as well as the hotel guests.

Sitting off in a corner of the ballroom was Californian Rod Diridon, chairman of the Santa Clara County Board of Supervisors, who announced elatedly that he had gotten in to see Energy Department officials yesterday and had come away with some answers about gas supplies. "They said there will be an audit of oil refineries in California to see why they're holding back on supplies." He also said he had learned that a new gas allocation plan would be completed by tomorrow. Diridon's county is one of several which began alternate-day gas rationing this week.

Senate Majority Leader Robert Byrd of West Virginia put on his red vest and took out his fiddle to warm up the crowd while everybody waited for the president to arrive. And there was some concern after a rambling dialogue that the president might never make it. "You thought you were going to hear 'Cumberland Gap' but let me say to Ted Kennedy [who was in the crowd] and President Carter," Byrd said, "that's just a bunch of baloney." This was a reference to last week's Democratic scuffling, when Carter termed Kennedy's criticism of his windfall profits tax plan "a bunch of baloney."

Carter almost had a triple play of success yesterday when he took Sen. Edward Kennedy away from a luncheon audience of Democratic supporters. But Kennedy, after being briefed on the SALT agreement, make it back. "He has a voice that won't quit," said Robert Smith, a vice president of E-systems, a Dallas-based electronics and aerospace firm. "But I'm not saying I agree with President Carter."

The evening got under way on the hotel terrace where free bars were strategically spaced not more than 20 feet apart and some lesser-known fiddlers played background music. The dinner wrapped up a two-day package of events for 259 Democratic House and Senate Council members, party stalwarts across the country who pay $1,500 a year for membership. Most of them were unfamiliar faces, except to each other. Some of them took entire tables of 10 ($10,000), others entertained congressional guests at small satellite parties in rooms ringing the terrace. Then there were lobbying groups such as the National Association of Homebuilders and the National Association of Homebuilders and the National Association of Realtors.

And labor leaders. And corporation executives. And longtime Democratic stalwarts mingling with the Cabinet members and administration officials.

And no matter what the political jousting, Pamela Harriman, the dinner cochairman, was elated over meeting the committee's $1.5-million goal. "We sent out over 30,000 letters. I did an average of 40 to 50 telephone calls every day for the last three weeks," said Harriman. Her won association with the Democratic party dates back to the 1930's in London when, she explained, "Kathleen Kennedy was my best friend." CAPTION: Picture 1, President Carter at the fund-raiser, by AP; Picture 2, George McGovern with Sen. and Mrs. Howard Metzenbaum, by Joe Heiberger