"That sounds lovely!" Hermione accepts his offer with a smile. She takes his offered hand to stand to her feet. Then she opens a small pouch at her side, and puts her book into it (even though the book itself is bigger). The disappearing book would be a strange sight, for one who might never been around magic.

"I'm Hermione Jean Granger. And you?" If she is going to have his company, she should learn his name.