Perhaps he had rigged up video cameras to film the students writing?
Perhaps they were all paid to agree with him, as part of some experiment to show how someone (e.g. you) reacts to impossible events?
There are many explanations that don't require the use of unevidenced techniques like ESP.
But there are also many explanations that
would require unevidenced factors.
Maybe the information was scanned by aliens and the put directly into his brain?
Maybe he froze time and read the papers while you were 'stuck' in time?
Which type of explanation do you think is more likely?
Our assignment was to research ESP and attempt to find a way to prove that his ESP is only a magic trick.
Try changing the circumstances of the trick.
Bring in your own sealed envelope with your own card with your name and a fact.
(Choose a fact from when you were a young child: something unrecorded e.g. You had a pair of shoes that you hated.)
Don't tell
anyone - including your friends.
Then ask the professor what the 'fact' is.
If he complains, then repeat the whole process - but in a room of your choosing, using your own card and envelope.
You might find this link interesting:
James Randi exposes Uri Geller and Peter Popoff - YouTube
It is particularly relevant at about the 6 minute mark.