Note that Acrobat and Acrobat Reader are two different products. As Zeke said, Acrobat (which is not free) can produce PDFs via virtual printer drivers.

However, the reason that you're having problems, to reiterate what every one else has said and to try to be extra-clear, is that you are simply embedding pictures of documents within a PDF file. The reason that PDFs are so small is that they generally only include the text and just enough ``mark-up'' to make them look right. It has no way to significantly reduce the pictures you're embedding, though.

Edit: Oops. Forgot to replace my xxx placeholder with Zeke (as I forgot who I was ``quoting''.