\usepackage{booktabs} % preamble \begin{tabular}{lccc} \toprule Case & Box A & Box B & Remarks \\ \midrule \multirow{2}{10mm}{A} & $+X$ & $-1.0$ & \\ \cmidrule(lr){2-3} & $-X$ & $-7.9$ & \\ \bottomrule \end{tabular}