\documentclass[11pt,a4paper]{article}
\usepackage{parskip}
%\usepackage{enumitem}
\usepackage{multirow}
\usepackage{rotating}
\usepackage{colortbl}
\begin{document}
\begin{tabular}{|>{\columncolor[gray]{0.95}}c p{11cm}|}
\hline
\rowcolor[gray]{0.85} \cellcolor[gray]{0.8}{\bfseries\scriptsize{}Group} & {\bfseries\scriptsize{}Elements} \\
\hline
	& Lorem ipsum:
	\begin{itemize}%[nolistsep]
		\item blah,
		\item blah,
		\item below you can see unwanted new line.
		%% UNWANTED NEW LINE
		% exists also w/o parskip package, when enumitem is used and nolistsep
		% option is provided to itemize environment
	\end{itemize} \\ \cline{2-2}
	& Something more\ldots \\ \cline{2-2}
	& Something more\ldots \\ \cline{2-2}
	& Something more\ldots \\ \cline{2-2}
	& Something more\ldots \\ \cline{2-2}
	& Something more\ldots \\ \cline{2-2}
	& Something more\ldots \\ \cline{2-2}
%% NO VERTICAL CENTERING
% is there any way to place rotated text in the middle (center it vertically)
% w/o manual tuning fixup value?
\multirow{-8}{*}[4.5em]{\rotatebox[origin=c]{90}{Text longer than 1st cell height}}
	& Something more\ldots \\
\hline
\end{tabular}
\end{document}
