There is only so much sadness you can take, and each of these is unbearably sad. Malamud's own parents were keepers of a small store, and theirs is the world that he writes about most - a sort of "lumpen-petit-bourgeoise", one notch above street peddlers (he also writes about those), who are notionally independent businesspeople but are actually as much victims of the market as those with nothing to sell but their labour power. Little shopkeepers going broke in the face of competition from discounting supermarkets, master tailors with two employees scratching a living...they are all here.
Everything in these people's lives is without joy - personal and family relations, employment, even their attempts to improve themselves through night school or artistic creation. The night school is particularly depressing, because it's impossible not to think of the knockabout comedy of Hyman Kaplan - the same subject, but a completely different tone and feeling.
Yet each story is perfectly crafted, and it's a marvel to see how well he does it. You just can't read too many at once.