Read books to learn something new and interesting, not to make an impression during the interview. Something that can be added to your knowledge base. If you read to impress the panel, you'll be more concerned with completing the number of books than with gaining a deeper understanding of the context, which can defeat the purpose of reading entirely. Keep in mind that some people can read quickly and with great comprehension. It could be a lifelong hobby for them. Maintain your current pace.
In terms of books, there are some common genres that can be good conversation topics during interviews, such as history, politics, innovation, literature, and so on, but read what interests you. Even if you're reading simple books like Harry Potter, it's fine as long as you can answer some good questions about what you've learned from the characters, incidents, or the book as a whole. Do read about the author and his/her other works as well. You will be questioned about other works by the same author or similar books that are available. Make sure you can explain why you chose a specific genre.