Some pdfs do already have a table of contents (that's what the icon in the tools menu is for). Adding a TOC without Adobe Acrobat is not very easy. It's possible to add them with ghostscript (in the form of bookmarks), but it requires some effort.
This is basically what you have to do if you want to add a table of contents to your existing pdf file:
http://blog.tremily.us/posts/PDF_boo...h_Ghostscript/