In theory you could take every book you own to a signing, though it doesnt mean you will get any signed. It is down to the Book Store (or other) who are holding the event to decide what they will accept. They do not have to allow you to bring ANY of your own books, as the purpose of getting Ray there, is primarily to publicise their store, and sell his book. Any additional books you can get signed is a bonus, so it is always advisable to contact the venue beforehand and ask if you are permitted to bring some of your own books along for signing, and if there is a limitation to numbers.
See also How many books will Ray sign for me at a signing?
admin: It is also good manners to purchase the book that is being signed from the Book Store, that is holding the event. Not only does this help keep them in business in the competative world of bookselling, but also an incentive to ask Ray to return at a later date, to sign a future book.
FAQ answers attributed to Raymond E. Feist are copyright by Raymond E. Feist.
It should also be born in mind that the answer given was only applicable on the date written, and to a specific question. You may find further, similar questions, in the FAQ.