Britain has been celebrating one of its strongest showings ever in the Olympics with relatively little thought about the boycott of the Moscow Games that Prime Minister Margaret Thatcher vigorously but vainly tried to pursuade British athletes to join.

The gold medal-winning performances in prestige track-and-field events such as the decathalon and the 100, 800, and 1,500 meter races have made front-page headlines and been featured on prime time television news. Sports columnists and editorial writers have argued that the British must not let the boycott prevent them from enjoying these moments of glory during the nation's frustrating economic decline.

"Even the tragedy of Russia's rape of Afghanistan cannot obscure the fact that Britain has something to cheer about in the magnificent victories at the Olympic Games," declared the tabloid Sun, Britain's largest circulation newspaper and normally a down-the-line supporter of Thatcher's policies.

"Apart from what the SAS [Special Air Services] did to the Iranian Embassy," wrote colmnist Ian Wooldridge of the ultraconservative Daily Mail from Moscow, referring to the rescue of nearly two dozen British and Iranian hostages in London last May, "nothing much has happened to make Britain feel prouder in several years."

Like other British sportswriters, he argued strenously that the British medals should not be considered tarnished by the boycott, contending that the British performances could have withstood American, West German or other competition from boycotting nations.

British Broadcasting Corp. and commercial television commentators have acknowledged the effect of the boycott only in competitions where the British have little interest, such as judo, which is usually dominated by the Japanese.

The extensive British television and newspaper coverage also has included much favorable comment about the Soviet facilities and hospitality, despite the rough treatment given some British photographers. The BBE featured interviews with Muscovites who insisted that they could not understand all the fuss over Afghanistan or why the Americans had engineered the boycott.

This was one of the few times Afghanistan has been mentioned in British coverage of the Olympics.

The BBC and the main commercial television network are each devoting 40 hours of air time to special coverage of the Olympics, much of it live via satellite. This is much less than the 190 to 180 hours of coverage each network had planned before Thatcher's government put pressure on them to make cuts and before the boycott so reduced the Games' program.

It appears that the boycott has boomeranged here, especially among the seeming majority of Britons who avidly follow sports.

It also had little effect in Scandinavia, except in Norway, where the spontaneous popular reaction against the Soviet invasion of Afghanistan was stronger to begin with. In addition, Scandinavians have relatively little interest in the Summer Olympics. A boycott of the Winter Olympics would have been a quite different thing.