any ideas about how to improve this table layout? IMHO it looks horrible.
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{booktabs}
\usepackage{makecell}
\usepackage{amsmath}
\begin{document}
\begin{table}[!h]
\centering
\begin{tabular}{c|c|c|c|c|c|c}
\toprule
\bfseries{Grandezza}&\bfseries{\makecell{Unità di \\ misura}}&\(\boldsymbol{t_a}\)&\(\boldsymbol{t_d}\)&\(\boldsymbol{t_p}\)&\bfseries{RMS}&\bfseries{Picco}\\ \hline \\[-1em]
\(\Delta t_i\) & \(s\) & 0.2 & 0.2 & 0.3 & &\\ \hline \\[-1em]
\(\dot{\theta}_{C}^{MAX}\) & \(rad/s\) & 7.85 & 7.85 & 0 & & 7.85 \\
\hline \\[-1em]
\(\overline{\dot{\theta}}_{C}\) & \(rad/s\) & 3.93 & 3.93 & 0 & 3.43 &
\\ \hline \\[-1em]
\(\ddot{\theta}_{C}^{MAX}\)& \(rad/s^{2}\) & 39.3 & -39.3 & 0 & 29.7 & 39.3 \\ \hline \\[-1em]
\(J_t\cdot\ddot{\theta}_{C}\)& \(Nm\) & 66.81 &-66.81 & 0 & & \\ \hline \\[-1em]
\(C_c\) & \(Nm\)& 1.4 & 1.4 & 0 & & \\ \hline \\[-1em]
\(C_{pd}\) & \(Nm\) & 0.3 & 0 & 0 & & \\ \hline \\[-1em]
\(C_v^{Picco}\) & \(Nm\) & 1.57 & 1.57 & 0 & & \\ \hline \\[-1em]
\(C_v^{Medio}\) & \(Nm\) & 0.79 & 0.79 & 0 & & \\ \hline \\[-1em]
\(C_R^{Picco}\) & \(Nm\) & 3.27 & 2.97 & 0 & & \\ \hline \\[-1em]
\(T_{2}^{Picco}\)&\(Nm\) & 70.1 & -63.8 & 0 & & 70.1 \\ \hline \\[-1em]
\(T_{2}^{Media}\)&\(Nm\) & 69.3 & -64.6 & 0 & 50.7 & \\ \hline \\[-1em]
Tipo di moto & - & Dir. & Retr. & - & & \\ \hline \\[-1em]
& & & & & & \\ \hline \\[-1em]
& & & & & & \\ \hline \\[-1em]
& & & & & & \\
\bottomrule
\end{tabular}
\caption{Tabella riassuntiva per il dimensionamento del riduttore della tavola rotante}
\label{tab:dimensionamento_tavola_rotante}
\end{table}
\end{document}
booktabs
and vertical lines are not intend to work together ...