Paperwork
From Official Office Management 101 Wiki
Paperwork is a byproduct generated by working on office tasks.
Generation of paperwork
You can generate paperwork passively, by working on project tasks (Engineering, Design, Testing, Managing). You can also do the "Write documentation" task, this will purposefully generate paperwork in order to gain "Company Experience" points.
Dealing with paperwork
To store paperwork the employees need at least one table with free space on then, otherwise the employee will complain and then place the paperwork on the ground, lowering its "Work quality" stat. After you got some paperwork you can combine then into paperwork boxes, as shown on the .gif below: