There are two main characters in the story, in terms of social importance. They are Mr. Summers, the wealthiest man in town, and Mr. Graves, the second most powerful man in town. Both men seem to be in charge of the proceedings, and their positions are generally and meekly accepted by the rest of the town.
The other characters are their "flock," so to speak. They are led by these men in carryiing out this age-old ritual.
Some critics suggest that these men represent the upper-class members of our society, while the rest of the town represents the working class.
The members of the society perceive the two "organizers" much the way they perceive everything else about this story: they take everything in stride; there is a pervasive sense that this day is simply "business as usual," which the reader believes until the story's end.
Summers and Graves are separate from the rest of the town because of their status, as well as the part they play in running the lottery. There is no overt indication that they are also a part of the lottery system (of if they are supposed to be, are they really? they organize the collection of the names...); it's impossible to know. However, it is their acceptance and governing of the process that allows it to move forward.
And while one character, Mr. Adams, questions the purpose of continuing the proceedings while other towns have stopped, his opinion is meaningless as he stands at the front of the group when the stoning begins.
I find Tessie Hutchison a worthy character to include in a list of characters. As a part of the "flock" it is almost as if Tessie had a sixth sense about that day. Did you notice she arrived to the drawing late, as in almost the last person there? People inquired as to where she was. It was almost as if she knew this would be her day. She happened to being finishing up a little bit of work in the kitchen.
Tessie might represent those in society who are aware enough to know that even though they follow most things blindly, every know and then it is easy to figure out that something bad is going to happen.
Tessie also had friends in the group. All the other housewives were the ones asking about her. This reveals to us something about societies. Even when it would seem prudent and wise do something about a situation (like, oh, say save your friend from being stoned to death when she has done nothing to deserve it), we don't do anything. This society should have revolted from the act of stoning an individual just because a token member of society should be killed to ensure the harvest is good. That's absurd! These friends allowing this to happen perpetuate a problem in society.