Goodby, Garrison : LEAVING HOME : A Collection of Lake Wobegon Stories <i> by Garrison Keillor (Viking: $18.95; 700 pp.) </i>

In his introduction, written from his new home in Copenhagen, Garrison Keillor recalls his monologues on the Prairie Home Companion radio show as “seances.” Exactly, and there must have been some nervousness about committing them to print.

But the spell holds. Those who enjoyed hearing the news from Lake Wobegon, Minn.--how Wally’s pontoon boat sank with the 24 Lutheran ministers on board; how Florian Krebsbach absent-mindedly left his wife Myrtle behind at the truck stop, to the refreshment of their marriage; how Lyle Krebsbach, Florian’s son, finally came to an understanding with himself about getting his roof fixed, although this would mean consulting his handy brother-in-law, Carl; how Clarence Bunsen found a new enlightenment after suffering a near-near-death experience (possibly) in the shower--will also enjoy reading about these adventures.

Keillor doesn’t ramble as much in type as he did on the air. That won’t bother everybody. But he still likes to head the story down a gravel turnoff and then, just when nothing at all looks familiar, hook up with the main highway. A little test of faith.

All that a devout Lake Wobegoner really needs to know about this book is that it’s out. However a few words may be in order for non-believers.

The objection seems to be that Keillor is the Norman Rockwell of the 1980s. I don’t see it. To begin with, there’s nothing picturesque about Lake Wobegon. It is your basic squat Minnesota hamlet, with its one blinking-yellow traffic light. In winter the typical vista is “a cold gray street lined with miserable yards.” In summer, the leading natural feature is the mosquitoes. Also, Lake Wobegon people are a little depressed because “living in Minnesota takes it out of you.” Not just because of the climate, but because in a town this size (fewer than 1,000), everybody knows your least little mistake. Try to hide it and you may have the town snickering all winter.

Lake Wobegon residents would do anything for a person if they figured that he really had a problem, but on the small issues they can be mean; and for Keillor it’s the small issues where life is decided--the little kindnesses as well as the slaps. Unlike most small-town satirists, he doesn’t attack the religiosity of his characters as hypocritical. He sees this as something absolutely called for, given our fallen natures.

Marriage also is a necessity, “because we can’t get attractive every day on a regular basis,” especially in winter. When a man really feels himself getting ugly, he goes and hunkers in the fish house, possibly with a bottle.

The Gospel According to Peanuts does not go on Lake Wobegon. “Shame,” for example, is as strong a force here as it is in Japan. And while Keillor wishes that his characters weren’t so prone to feeling guilty about themselves--especially the young people--he nevertheless prefers this to letting it all hang out. Better repression than tackiness.

Take the “expert” from the city who screwed up a fireplace job for Clarence Bunsen and then insisted on sharing his feelings on this disaster with Clarence over the phone, rather than coming back to fix the thing.

The guy turned out to be from L.A. Lake Wobegon people know all about Los Angeles (they are on cable), and they pity anybody who would have to live there, except during late March.

Keillor approves his characters’ distrust of facile emotion--of facile anything . But he worries that they are too wrapped-up in doing the next thing to see the big picture. Like Emily in “Our Town,” he wants them to see how wonderful it all is, while there’s time. This leads to some praise-to-the-morning finales that don’t work as well in type as they did on the radio, the listener not having been softened up by an hour of bluegrass guitar and hymns.

But something else comes across better on the page: the realization that Lake Wobegon does not exist. This is not news when you think about it, but usually we haven’t thought about it. There’s been something very solid about the Sidetrack Tap and the Chatterbox Cafe.

Here, though, every now and then, the whole town starts to waver, like a mirage, and you see Keillor, the Maker, wondering whether to send a character into her house to discover the mess that her kids have made, or to let her take a walk around the block first. It’s a responsible job, running a universe.