Short word that means "someone who takes notes"

Scribe is one of the shortest words for "one who transcribes professionally".

It's difficult to be precise and short sometimes: a clerk might take notes, but probably doesn't do this as a sole task.

Some longer but more precise alternatives are notetaker or transcriptionist.

You could try amanuensis:

a person employed to write what another dictates or to copy what has been written by another; secretary.

[Dictionary.com]

How about "rapporteur?" An old French word for someone who reports. It's a term used at the United Nations and other international organizations.

a person who is appointed by an organization to report on the proceedings of its meetings.

[Wikipedia]