What is the purpose of listing all the names at the beginning of chapter 4?

This is so we get a sense of the type of people who come to Gatsby's parties. There is a theme here. They are generally rich and have little interest in Gatsby himself (other than the mystery behind him). Fitzgerald generally describes them as self-absorbed and only interested in the excess of the party, "the people came like moths to the flame."

What is the purpose to listing all the names in the beginning of chapter 4?