How many books have you read

How many books have you read
 

-How many books have you read?/How often do you read books?

Can I say: in reply:

-Not much.

and explain it inwardly by saying the underlying meaning is

-not much reading (=not many books)

Yes. but the explanation is "haven't done much reading, lately"

How many books have you read?
Not many. Many. Quite a lot/few.

How often do you read books?
Not often. A lot. Not enough/too much.

Thank you~

But is that conversation I quoted possible in daily life?

The answer to "How many ..." should not be "Not much." "Not many" is correct.
The answer to "How often ..." may be "Not much." "Not many" is not correct.

Thank you~