In "Kill Bill: Part II" Estaban Viejo is reading a book entitled "the
Carrucais of Kurrangong" by Jasmin Yuen. Is this a real author and a
real book? Why is Estaban's character given this book to read?

The name of the book that Esteban is reading is "The Carrucan's of
Kurrajon," by Jasmine Yuen.

This is not a real book; the book functions not only as a prop but as
an inside joke. It's a tribute to a member of the film crew, Jasmine
Yuen Carrucan. Kurrajong is a town in Australia; Jasmine Yuen Carrucan
is Australian.

"Jasmine Yuen Carrucan ....  editorial production assistant  
 Jasmine Yuen Carrucan ....  second assistant camera"

Internet Movie Database: Kill Bill: Vol. 2
http://imdb.com/title/tt0378194/fullcredits

Quentin Tarantino, who directed the "Kill Bill" films, is well known
for filling his films with inside jokes and obscure references. Some
of these (including Esteban's book) are discussed here:

The John Crichton Guide To Pop Culture: Kill Bill
http://www.chairmanmorris.com/crichton.htm

Google search strategy:

Google Web Search: jasmine yuen carrucan kurrajong
://www.google.com/search?hl=en&q=jasmine+yuen+carrucan+kurrajong

I hope this is precisely what you need to know. If anything is unclear
or incomplete, please request clarification; I'll gladly offer further
assistance before you rate my answer.

Best regards,
pinkfreud

quick, clear and accurate...thankyou

For anyone interested in "Kill Bill" trivia, there are some quizzes here:

Fun Trivia: Kill Bill
http://www.funtrivia.com/quizzes/movies/movies_h-k/kill_bill_.html