copyholder n : mechanical device used in printing; holds the copy for the compositor
A copyholder is a device that holds written material for typing. They have been used with typewriters or more often on a computer word processor.
Some stand independently or are attached to a computer monitor. They can support entire booklets or a single page. Elaborate varieties even can be adjusted by height or angle and even come with rulers and guides that appear over the front of the page.
A copyholder is also someone who holds land by means of copyhold.