Can't copy text from a pdf file

The pdf file has probably been locked against copying text. Below are two ways to unlock it:

1. If the pdf has not been locked against printing, you can print it to a virtual pdf printer to create an unlocked file. See this:
   "Remove Password and Unlock Protected PDF Which Allowed To Be Printed Without Knowing Secret".
2. If the print function has been locked out, see this :
   "Remove Restrictions and Decrypt Password Protected PDF Files With PDF Unlocker".

1. Open the PDF in Google Chrome(drag and drop PDF file to Chrome).
2. Print the particular page as PDF or just open print preview.
3. Now you can copy the text from print preview or output PDF. But I don't think you could copy the table directly.

I was able to create a DRM-free version of your PDF file using Ghostscript (which is available for Windows).

gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=stripped.pdf VassilakisP2001Dissertation.pdf

The resulting file stripped.pdf can be loaded in Adobe Reader, and Reader will happily allow you to copy any part of it you wish. It also preserves most of the formatting of the table.