\documentclass[border=5mm]{standalone}
\usepackage{tabularx,siunitx,multicol,ragged2e}
\usepackage[table]{xcolor}


\newcolumntype{Y}{>{\Centering}X}
\newcolumntype{L}{>{\RaggedRight}X}
\newcolumntype{R}{>{\RaggedLeft}X}

\begin{document}
	\setlength{\tabcolsep}{0pt}
	\rowcolors{2}{gray!20}{}
	\begin{tabularx}{1\linewidth}{
			>{\hsize=1.3\hsize}L@{\hspace{5ex}}
			>{\hsize=0.7\hsize}L
			S[table-format=3.1, round-precision=1, table-column-width = 0.2\linewidth, table-number-alignment=right, table-space-text-post=\hspace{1ex}]
			s[table-unit-alignment = left, table-column-width = 0.2\linewidth]
		}
		Parameter & Symbol & \multicolumn{2}{c}{Value}\\
		Inertia Inertia Inertia Inertia Inertia Inertia Inertia Inertia Inertia Inertia Inertia Inertia Inertia Inertia Inertia   & $J_M$ & 0.6 & \kilogram\m\squared\\
		Inertia  & $J_M$ & 0.6 & \kilogram\m\squared\\
		Inertia  & $J_M$ & 0 & \kilogram\m\squared\\
	\end{tabularx}
\end{document}