Isso foi tirado na íntegra de @Herbert, respondendo a uma pergunta muito semelhante no TeX StackExchange:
Adicionando o sumário ao PDF existente
use o pacote pdfpages
e, em seguida:
\documentclass{article}
\usepackage{pdfpages}
\usepackage{hyperref}
\begin{document}
\tableofcontents
\clearpage\phantomsection
\addcontentsline{toc}{section}{The first section name}% or chapter
\includepdf[pages={1-10},linktodoc,linktodocfit=/Fit]{texte/dtk/dtk11-1/komoedie.pdf}
\clearpage\phantomsection
\addcontentsline{toc}{section}{The second section name}% or chapter
\includepdf[pages={11-19},linktodoc,linktodocfit=/Fit]{texte/dtk/dtk11-1/komoedie.pdf}
\clearpage\phantomsection
\addcontentsline{toc}{section}{The third section name}% or chapter
\includepdf[pages={20-29},linktodoc,linktodocfit=/Fit]{texte/dtk/dtk11-1/komoedie.pdf}
\clearpage\phantomsection
\addcontentsline{toc}{section}{The forth section name}% or chapter
\includepdf[pages={21-39},linktodoc,linktodocfit=/Fit]{texte/dtk/dtk11-1/komoedie.pdf}
\end{document}