The first table does not include the before
and after
options in order to correct the spacing above and below the itemize
environment.
The second table includes these options. As one can see, the negative vspace
s interfere with nested itemize
environments, as they add up.
The third table does again not contain the before
and after
options, but includes some manual adjustments in order to get rid of the unnecessary white space above and below the first level itemize
environment.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{tabularx}
\usepackage{enumitem}
\begin{document}
\begin{center}
\setlist[itemize]{nosep,
topsep= 0pt,
partopsep=0pt,
leftmargin= *,
label=\textendash,
%before=\vspace{-0.6\baselineskip},
%after=\vspace{-\baselineskip}
}
\begin{tabularx}{\linewidth}{ | l | X | }
\hline
Description & \begin{itemize}
\item long text bla bla bla bla
\item long text bla bla bla bla
\item long text bla bla bla bla
\item long text bla bla bla bla
\begin{itemize}
\item short text
\item short text
\end{itemize}
\end{itemize} \\
\hline
Addition & long text bla bla bla bla long text bla bla bla bla\\
\hline
\end{tabularx}
\end{center}
\begin{center}
\setlist[itemize]{nosep,
topsep= 0pt,
partopsep=0pt,
leftmargin= *,
label=\textendash,
before=\vspace{-0.6\baselineskip},
after=\vspace{-\baselineskip}
}
\begin{tabularx}{\linewidth}{ | l | X | }
\hline
Description & \begin{itemize}
\item long text bla bla bla bla
\item long text bla bla bla bla
\item long text bla bla bla bla
\item long text bla bla bla bla
\begin{itemize}
\item short text
\item short text
\end{itemize}
\end{itemize} \\
\hline
Addition & long text bla bla bla bla long text bla bla bla bla\\
\hline
\end{tabularx}
\end{center}
\begin{center}
\setlist[itemize]{nosep,
topsep= 0pt,
partopsep=0pt,
leftmargin= *,
label=\textendash,
%before=\vspace{-0.6\baselineskip},
%after=\vspace{-\baselineskip}
}
\begin{tabularx}{\linewidth}{ | l | X | }
\hline
Description & \begin{itemize} \vspace{-0.6\baselineskip}
\item long text bla bla bla bla
\item long text bla bla bla bla
\item long text bla bla bla bla
\item long text bla bla bla bla
\begin{itemize}
\item short text
\item short text
\end{itemize}\vspace{-\baselineskip}
\end{itemize} \\
\hline
Addition & long text bla bla bla bla long text bla bla bla bla\\
\hline
\end{tabularx}
\end{center}
\end{document}
The last table can also be produced with the following MWE, which makes use of two different, new defined itemize
-like environments for first-level and subsequent-level itemize
environments inside table cells:
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{tabularx}
\usepackage{enumitem}
\newlist{tabitemizefirst}{itemize}{1}
\newlist{tabitemizesecond}{itemize}{1}
\setlist[tabitemizefirst]{nosep,
topsep= 0pt,
partopsep=0pt,
leftmargin= *,
label=\textendash,
before=\vspace{-0.6\baselineskip},
after=\vspace{-\baselineskip}
}
\setlist[tabitemizesecond]{nosep,
topsep= 0pt,
partopsep=0pt,
leftmargin= *,
label=\textendash,
}
\begin{document}
\begin{tabularx}{\linewidth}{ | l | X | }
\hline
Description & \begin{tabitemizefirst}
\item long text bla bla bla bla
\item long text bla bla bla bla
\item long text bla bla bla bla
\item long text bla bla bla bla
\begin{tabitemizesecond}
\item short text
\item short text
\end{tabitemizesecond}
\end{tabitemizefirst} \\
\hline
Addition & long text bla bla bla bla long text bla bla bla bla\\
\hline
\end{tabularx}
\end{document}
before
andafter
options ofsetlist
). They interfere with the nesteditemize
enviroment.