Concerning Eliot's "The Love Song of J. Alfred Prufrock," the name Eliot uses is considered to be highly stylized. This is probably the most important aspect of the name.
The name does suggest a businessman, also, but this is probably not so vital.
The name, J. Alfred Prufrock, being so formal, contrasts with what one usually thinks of with the words: love song. And that's the point. In other words, the connotations, or word associations, of "J. Alfred Prufrock," contrast with the connotations of "love song."
That is the speaker's state of existence. He contrasts with anything that can be termed a love song. He is socially inept. He is on his way to ask a woman some vital question during tea, and he never even makes it there.
He is isolated and alienated and socially ineffective. His love song is not much of one.
This contrast, by extension, is also the state of modern man. Humans are alienated and isolated, and the speaker represents all of us.