If your child is eating paper it could be that the child is just bored and wants something to do so they chew on paper.
It's unlikely that the child is actually eating the paper as in swallowing the paper but chewing on paper in normal in children.
Some children chew on paper, erasers, pencils, pens, fingernails etc as a way to relive boredom or even stress.
If the child is anxious or stressed out or just plain bored the child may chew on paper or eat paper or even chew on their shirt or even hair.
When I was bored in class as a kindergarten student I would chew on my paper as a way to relive that boredom as well as stress.