Provide contents of file field at node URL
Its not a good idea to provide contents of file field at node URL.

Instead use File Aliases module which will let you use node properties in the resulting file url.


  The File Aliases module allows you to use token customizable aliases
  for your uploaded files, giving you the ability to keep your file
  system organized as per usual while providing clean looking paths
  (i.e., no more '/sites/default/files/').