% TOC bookmark solution found here:
% https://tex.stackexchange.com/questions/97024/how-to-add-the-pdf-bookmark-of-toc-without-its-name-contents-in-toc
\clearpage
\fancyhead[L]{Περιεχόμενα}
\fancyhead[R]{}
\pdfbookmark{\contentsname}{toc}
\tableofcontents \label{toc}