The form appears to be very large and is composed of many pieces of paper. It is unknown what is in it, but it most likely contains agreements for an employee at the Krusty Krab.
Role in episode
When Plankton is controlling Sandy's pelt, he asks SpongeBob how he makes a Krabby Patty. SpongeBob responds that he cannot do that, due to his current labor contract. He then shows Plankton the Krusty Krab Industries Labor Agreement. Plankton tries to argue that they are close friends, but SpongeBob shows him a specific section of the labor agreement that forbids the disclosure of the secret formula even to close friends.
According to SpongeBob, section 44-929b specifically prohibits the disclosure of the secret formula to friends, even when those friends are "closer 'n two catfish in a skillet."