Yes. You can download it using the Safari browser and read it that way.
You can also download the book to your desktop or laptop, then email yourself the book as an attachment, and open it on your iPad. Pinch and zoom to size the PDF on your screen.
There are also several apps in the Apple App Store for reading PDFs. GoodReader is a nice one, and it costs only 99¢. There are also some free ones: Try iBooks, CloudReaders, or Stanza.