I'm not sure specifically as I haven't read it in detail. But I assume the 'Jealousy Man' is one of the main characters. There may be others who are related to him in some way, like friends or family members who are affected by his jealousy.
Since I haven't read the book myself, it's hard to say exactly. However, given the title, the 'Jealousy Man' is likely a central character. He might be surrounded by characters who either fuel his jealousy or are the victims of it. There could be a love interest perhaps, or a rival that causes the jealousy to flare up. And there may be other characters in the 'other stories' part of the book who each have their own story arcs and personalities.
I'm not entirely sure without having read it in detail, but likely there are characters that represent different aspects of the society depicted in the book. Maybe there is a push man who could be central, perhaps someone who is constantly in a position of having to push forward in a difficult life.
I'm not entirely sure without reading it specifically, but typically in such a work, there would likely be an ordinary man as one of the main characters, and then perhaps a character representing the superman. There could also be supporting characters like friends, family, or antagonists.
The man upstairs is likely one of the main characters. But without reading it, it's hard to say who else exactly.
The main character is clearly the man with the scar. But there might be other supporting characters who interact with him and whose stories are also told in relation to his. Maybe a friend or a family member who has a different perspective on the man with the scar.
The Gingerbread Man is obviously a main character. And often there are animals like the fox, the cow, and the horse who are also important as they are the ones chasing the Gingerbread Man.
Since it's a collection of stories, there are likely to be multiple main characters across the different tales. In the story 'The Third Man', perhaps there is a character who discovers the presence of the third man, and this discovery drives the plot. In other stories, there could be characters who are dealing with personal problems or are involved in some sort of intrigue.
The Donkey Man is surely a main character. He might be accompanied by his donkey, which could also be considered as an important character in a way. There may also be characters such as the villagers or townspeople who interact with the Donkey Man. They could play important roles in the stories, for example, some might be his friends, some his foes, and others just bystanders whose lives cross paths with the Donkey Man's.
The master and the man are central. The master, who likely represents a certain social class or a set of values, and the man, who may be in a subservient position. However, in the other stories, there could be different characters like villagers, merchants or travelers that play key roles in the narrative, each with their own personalities and motives.
Obviously, the old man is one of the main characters. But there may be others like his family members, friends, or neighbors who play important roles in the stories.
The main character in the collection's title story is the Bicentennial Man. He is an android who starts with a basic programming but over the course of two hundred years develops emotions, desires, and a sense of self. Other characters in the story include the humans he interacts with, such as the family that owns him at the beginning. These human characters play important roles in his development. They can be accepting at times, and at other times, they are a source of conflict for the Bicentennial Man as he tries to break free from the limitations society places on him because of his robotic nature.