Welcome to Javaranch !!!
I have never used object tags but can you try reducing width and height to let us say 50%. Better if we can give width and height in pixels (for example - width=300 , height=200) . try this change and let us know if this has resolved your problem or not.
Rendering PDF in HTML Page may not work on all browsers. It depends on how the browser handles PDF files. Some browsers can render PDF directly in HTML page and some browser try to download it.
You can check PDFObject JS library
http://pdfobject.com/ specially meant for displaying PDF in HTML Page. This website say that this library take care of browser compatibility issues.
~ abhay
Oracle certified JPA Developer (1Z0-898),Oracle certified Java 8 Programmer I (1Z0-808), Oracle Java Web Service Developer (1z0-897), Oracle certified Java 7 Programmer, SCJA 1.0, SCJP 5.0, SCWCD 5.0, Oracle SQL Fundamentals I, CIW Certified Ecommerce specialist