Recently, I bought “Essential RenderMan Fast Book”, and I found that the book has missing pages, from page 245- to page276.

I can not believe it how the publisher made the mistake. You got the same problem if you have the book already? please confirm it.

there is nothing on the Errata page about it…
I'd just take it back to where you bought it and get a new one (or keep it in the vain hope that it will be a collectors item )
you can e-mail the author and let him know also:
ian@dctsystems.freeserve.co.uk