"One more reading would help you understand the meaning."
Well, it's not a polite request (3.), so that's out, and it's not a consent (1.), so that's out too, and it's neither a habit (4.) or a possibility (5.), so both of those are out, which leaves 2., a condition:
"If you read it again, one more reading would help you understand the meaning."
1. The door would not open. (consent)
EX:They would not help us with the homework. (consent)
2. If I were you, I would not go. (condition)
EX:It would have been too stale to eat, if we hadn't eaten it. (condition)
3. I would like to say a few words. (polite request)
EX:Would you like some coffee? (polite request)
4. We would often go to the movies. (habit)
EX:He would wait every day in the rain for her to walk by. (habit)
5. She would be over fifty by now. (probability)