By trying to compile the code below the following error will be raised for each \item entry.
Something's wrong--perhaps a missing \item
\begin{tabular}{ll}
560 v. Chr. & \begin{itemize}
\item erster Eintrag
\item zweiter Eintrag
\item dritter Eintrag
\end{itemize} \\
\end{tabular}

tabularx'sXoption, i.e. not specifying the width of the column withp{}, but adjusting it dynamically as 1/3 of\linewidth? My header would be\begin{tabularx}{\linewidth}{X | X | X }– Marie. P. Jul 12 '21 at 18:03