IT'S BECOMING FASHIONABLE to grumble that the 96th Congress is a little dull. Beyond the budget battle that just ended and the daily wrangling over gas supplies, little that's interesting is going on. That's the complaint. And there is something to it. If you define an interesting Congress as one that works at a supercharged rate, with members constantly whooping off in all directions, the last one was positively enchanting and this one very subdued.

Consider some basic indices of congressional activity. By May 23, 1977, the 95th Congress had sent the White House 40 bills, including some huge economic-stimulus packages. Through Wednesday, the 96th had cleared 12 measures, most of which are small. Compared with two years ago, the number of roll calls is down 30 percent in the Senate and 39 percent in the House. By this time in 1977, over 10,500 bills had been introduced; about 6,500 have been dropped in the hoppers this year. Finally, while the Congressional Record had not really been slim, it has been thinner-12,806 pages (not counting daily digests) through Wednesday, which is 3,685 fewer that two years ago.

True, the last Congress set off at an exceptional pace. After eight years of wrestling with Republican presidents, the Democratic majority had a big back-log of pet bills ready to go. President Carter piled on a huge agenda, too. This year everyone's lists have been much shorter-partly because that last Congress did so much, but even more because the economic and political climates have changed.

In a year of budget-cutting and government-pruning, many incumbents are reining in some time-honored promotional activities. They have grown less inclined to whip up a bill to solve every problem or serve each interest that comes along. Many have also curbed their habit of using the Record as a billboard for folksy notices about home-town events, winners of high school essay contests and the like.

What are the gains from this new selectivity? Some money is being saved; printing 3,685 more Record pages this year would have cost over $1.4 million.Each bill and press release forgone has also saved more of someone's time and energy than you might think. Ideally, the slower pace-though far from leisurely-will enable Congress to concentrate much more on oversight, careful pruning of programs, and the general retrenching that is now the major theme. It's too soon to tell about that. But when you recall one more statistic-that, according to one study a while ago, the average House member had 11 minutes per day to think-any move to slow the pace and cut the clutter is encouraging.