I'm using the multirow package to have multiple elements in the same row.
\begin{table}[!h]
\centering
\resizebox{1.0\textwidth}{!}{%
\begin{tabular}{l*{4}{c}|cc|c}
& \mathcal{D} & $\rho$ & $N_c$ & $N_C^{inv}$ & $C$ & $C^{inv}$ & $Q$\\
\hline
\multirow{2}{*}{Mod0} & \num{9.99} & \num{1.36e+1} & \num{3.32} & \num{7.05e+1} & \num{4.69e-3} & \num{6.59e-2} & \num{1} \\
& \num{-9.10} & \num{3.69e-1} & \num{-1.70e+1} & \num{-6.36e-2} & & &\num{1} \\ \hline
Mod1 & \num{1.94e+1} & \num{1.60e+1} & \num{8.65e+1} & \num{1.86e+2} & \num{} \\
\end{tabular}%
}
\end{table}
For the columns C and C^{inv} there is just one element (instead of two) and therefore I would like the single element to be in the centre of the line and not in the upper side. How can I do that?
The packages I'm using:
\documentclass[12pt, a4paper]{article}
\usepackage{siunitx}
\usepackage{enumitem}
\usepackage{verbatim}
\usepackage{multicol}
\usepackage{ dsfont }
\usepackage{xcolor}
\usepackage{movie15}
\usepackage[hidelinks]{hyperref}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{mhchem}
\setcounter{MaxMatrixCols}{12}
\usepackage{commath}
\usepackage{graphicx}
\usepackage{movie15}
\usepackage{hyperref}
\usepackage{wrapfig}
\usepackage{tabularx}
\usepackage{booktabs}
\usepackage{multirow}
\usepackage{float}
\usepackage[margin=2cm,left=2.5cm,includefoot]{geometry}
\usepackage{lipsum}
\usepackage{subfig}
\usepackage{subfigure}
\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhead{}
\fancyfoot{}
\fancyfoot[R]{ \thepage\ }
\renewcommand{\headrulewidth}{1pt}
\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhead{}
\fancyfoot{}
\fancyfoot[R]{ \thepage\ }
\renewcommand{\headrulewidth}{1pt}
\renewcommand*\listtablename{Elenco Tabelle}
\renewcommand*\contentsname{Indice}
\usepackage{pythontex}
\usepackage{minted}
You can use \multirow{2}{*}{...}
to place the content in the centre of the two rows
Off-topic:
there are serve package incompatibilities in your preamble. You must not ignore such error messages and clean up incompatible packages
you must not use \mathcal
outside math mode. An error message will tell you this. You must not ignore error messages
don't use \resizebox
for things that contains text. If you really must change the size, use an appropriate font size instead
don't use h!
as floating specifier. This will only result in bad float placement. Let latex do what it can do best and use htbp
don't load the same package multiple times
\documentclass{article}
\usepackage{siunitx}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{multirow}
\usepackage{float}
\usepackage[margin=2cm,left=2.5cm,includefoot]{geometry}
\begin{document}
\begin{table}[htbp]
\centering
%\resizebox{1.0\textwidth}{!}{%
\begin{tabular}{@{}l*{4}{c}|cc|c@{}}
& $\mathcal{D}$ & $\rho$ & $N_c$ & $N_C^{inv}$ & $C$ & $C^{inv}$ & $Q$\\
\hline
\multirow{2}{*}{Mod0} & \num{9.99} & \num{1.36e+1} & \num{3.32} & \num{7.05e+1} & \multirow{2}{*}{\num{4.69e-3}} & \multirow{2}{*}{\num{6.59e-2}} & \num{1} \\
& \num{-9.10} & \num{3.69e-1} & \num{-1.70e+1} & \num{-6.36e-2} & & &\num{1} \\ \hline
Mod1 & \num{1.94e+1} & \num{1.60e+1} & \num{8.65e+1} & \num{1.86e+2} & \num{} \\
\end{tabular}%
%}
\end{table}
\end{document}