Real Dictionary

pencil pusher
countable noun: If you call someone a pencil pusher, you mean that their work consists of writing or dealing with documents, and does not seem very useful or important.

pencil pusher in British English
a person, as a clerk or bookkeeper, whose work involves a considerable amount of writing, record-keeping, etc
a person, as an office clerk, whose job entails writing, keeping records, etc.
noun: a person who writes a lot, esp a clerk involved with boring paperwork