How do i answer the “List the titles of the required readings from courses during the school year or summer that you enjoyed most in the past year” question if my school doesn’t have required readings?
In the past year in your English or history classes you had absolutely no assigned readings other than a textbook?
Edited to add: OK, I see that you are an international student, so I will amend the above question to include native language literature classes.
We don’t have any classes outside of the subjects we choose. 
They only offer science and business subjects at most schools here.
Answer it honestly. Say none, with an explanation that your school had no required readings because they only offer science and business subjects. Then add a couple of titles of readings you enjoyed on your own, that were not required.
Ask yourself “Why is Columbia asking this question?” They will tell applicants in the information session that they are trying to find out more about you as a person, what you like and don’t like, to see how you’ll fit.
This is not a trap question, unless perhaps you don’t spell check and indicate you liked Shakeyspeer
thank you!