As is often the case with Melville. I do not know what this book really means. It reads like Kafka decades before Kafka wrote. Bartleby becomes an immovable presence in an office, while the narrator fails to dislodge him from the office and eventually the narrator moves his whole office.
Just when you get acclimatized to the book, it all shifts and Bartleby becomes a kind of hero and a stand in for the human condition, who drops out of existence itself.
I don't really know what it means, but its well worth reading.