What are the technique and purpose of the introductory chapters of "Tom Jones"?

Fielding employs a variety of literary techniques to tell the story. He combines epic, picaresque, and epistolary forms. The technique that might be confusing is picaresque. Picaresque means "one thing after another". The only element that seems to be common in the chapters would be the character. The story does not advance, but it is meant to be a satirizing of the society he lives.

Fielding also uses the epistolary form which moves the plot through letters. This is a useful technique when the characters are separated by distance. The plot/story is told through the letters rather than direct conversation.