This is the 16221st most frequent Russian word.
рассказов
The word "рассказов" is the genitive plural form of "рассказ," meaning "of stories" or "of tales."
In this sentence, 'рассказами' is an instrumental plural form used to complement the subject, indicating the objects of interest being stories in old books.
Она всегда читает старые книги с интересными рассказами.
She always reads old books with interesting stories.
Here, 'рассказов' is a plural genitive form, indicating the stories as part of the collection.
Его коллекция включает множество рассказов различных авторов.
His collection includes numerous stories by various authors.
In this case, 'рассказов' serves as a plural genitive form, denoting the stories as part of a quantity that was read.