Michel Tremblay's Stories for Late Night Drinkers, is a very early work. Rather than being an investigation of working-class Montreal (like most of his later novels and plays), these are short, fantastic fables largely in line with the unsanitized version of the Grimm fairy tales. I wouldn't say any are truly science-fiction tales (aside possibly from The Thimble), though there is one that falls into the vein of Lovecraft's Cthulhu Mythos (The Warugoth-Shala and possibly The Octagonal Room). Some go a bit further into fantasy than the Grimm tales, which generally stop at witchcraft. Lady Barbara's Last Outing and Wolfgang, on His Return both involve demons; there a story about a werewolf and perhaps vampires also appear. Tremblay seems to be skipping around all kinds of legends and fantastical tropes. It is even possible for Gentle Warmth to occur in real life, though it certainly reads like an urban legend of a crazy aristocrat who roasts women alive in a metal dress.
What links nearly all the stories is cruelty. Often, though not always, unwarranted cruelty is visited upon one character or another. To some extent, this is just the nature of fairy tales and legends more broadly. They seek to understand why evil events strike, particularly when the person being stricken does not appear to deserve such treatment (pace Job). More sophisticated cultures basically finally settled that bad luck could strike anywhere (this seems to be the case in Wolfgang, on His Return). Often the European legends settled on a the formula of people without protectors (i.e. orphans or near orphans like Hansel and Gretel) who are just a bit weak and/or greedy. We see this in Gentle Warmth. I would say that it is the more naive or superstitious cultures than insist that people with bad luck actually brought it upon themselves by 1) inadvertently insulting a witch (The Thimble) or 2) actually being witches in league with the devil. Tremblay doesn't really hold with this (I don't think), though The Bluebottles comes pretty close. I would say that Arthur Miller's The Crucible portrays (in a somewhat heavy-handed manner) the kind of society that insists there are no innocent victims, because their belief that if God were good and all-powerful, he wouldn't allow bad things to happen to good people.
So I understand what he is doing with these tales for drinkers. However, they are generally very short and not really engaging, partly because they are so short. I never felt invested with the characters, and perhaps I wasn't supposed to. I really thought The Thimble was silly, sort of a throw-away idea, and I really didn't care for Amenachem, where the plot was totally driven by incest. I thought Jocelyn, My Son was fairly successful. My favorite was probably Mr. Blink, where a man wakes up to find out he has become a candidate for Prime Minister. Some shades of Being There perhaps.
Quick note, somehow I stopped reading without reaching the final story
"The Devil and the Mushroom" which is a fable/parable of a peaceful
country where the devil has forgotten to invent war. It's certainly in line with the broader question of why is there evil in the world. One answer of course is that there is an evil agent, trying to stir up trouble. This eventually leads to very difficult theological questions of why would a good God allow this to happen, but we'll skip over that was now. It actually is one of the more successful stories, along with Mr. Blink. But as Milton found out, the Devil always gets the best lines.
It's an interesting start for a major Canadian literary figure, and The City in the Egg, apparently continues in this direction. (Not sure I will read this novel, or certainly not any time soon.) After this, Tremblay started working in a much more realistic vein, though there were some departures into experimental theatre (Albertine in Five Times and The Real World?). If one is looking to delve into Tremblay's work in a big way (and I expect I will over time), then one could certainly start here. Otherwise, it probably makes the most sense to work through his novels of Montreal, starting with The Fat Woman Next Door is Pregnant, or his less experimental plays: Les Belles Soeurs if one doesn't mind downbeat theatre or For the Pleasure of Seeing Her Again if one is looking for a sentimental and a bit uplifting evening out (assuming one has a choice of Tremblay productions to see, which is no sure thing outside of Quebec).