\documentclass{article}

\usepackage{geometry}
\usepackage[dutch]{babel}
\usepackage{parskip}
\usepackage{amsmath,amssymb}
\usepackage{graphicx,subcaption}
\usepackage{xcolor}
\usepackage{adjustbox}
\usepackage{booktabs}
\usepackage{tabularx}

\geometry{
	paperwidth=9cm,
	paperheight=7.5cm,
	margin=0.0cm,
    paperheight=5.5cm
}

\begin{document}

\begin{table}[htbp]
    \centering
    \begin{tabular}{c c p{2cm}}
        \toprule
        Getal 1 & Getal 2 & Notitie\\
        \cmidrule(lr){1-2}\cmidrule(lr){3-3}
        88 & 94 & Twee grote getallen\\
        89 & 12 & Een grote en een kleintje\\
        96 & 18 & Weer zo\\
        32 & 98 & Iets minder schreef\\
        \midrule
        \multicolumn{2}{c}{527} & Totale som\\
        \bottomrule
    \end{tabular}
    \caption{Een tabel!}
\end{table}

\end{document}