Problem with multi row table

Question

I'm trying to make this work, but the small cells don't show their content

\documentclass{article}
\usepackage{graphicx} % Required for inserting images
\usepackage{tabularray}

\begin{document}

\begin{table}
\centering
\begin{tblr}{hlines, vlines, colspec={ll}}
\SetCell[r=6]{} Expression
    & \SetCell[r=3]{} Modality
    & P                         \\
    & O                         \\
    & A                         \\
    & \SetCell[r=3]{} Expressive Symbols
    & P                         \\
    & O                         \\
    & A                         \\
\end{tblr}
\caption{The Audit CheckList}
\label{table:DesignPrinciples}
\end{table}


\end{document}

Answer 1

You want three columns, but you are only specifying two: {ll} should be {lll}.

\documentclass{article}
\usepackage{graphicx} % Required for inserting images
\usepackage{tabularray}

\begin{document}
    
\begin{table}
\centering
\begin{tblr}{hlines, vlines, colspec={lll}}
\multirow[c]{6}{2cm}{Expression} & \multirow[c]{3}{3cm}{Modality} & P   \\
   & & O  \\
   & & A  \\
    & \multirow[c]{3}{1.5cm}{Expressive Symbols} & P \\
   & & O  \\
   & & A  \\
\end{tblr}
\caption{The Audit CheckList}
\label{table:DesignPrinciples}
\end{table}


\end{document}

You could also use \multirow:

\documentclass{article}
\usepackage{graphicx} % Required for inserting images
\usepackage{tabularray}

\begin{document}

\begin{table}
\centering
\begin{tblr}{hlines, vlines, colspec={lll}}
\multirow[c]{6}{2cm}{Expression} & \multirow[c]{3}{3cm}{Modality} & P   \\
   & & O  \\
   & & A  \\
    & \multirow[c]{3}{1cm}{Expressive Symbols} & P \\
   & & O  \\
   & & A  \\
\end{tblr}
\caption{The Audit CheckList}
\label{table:DesignPrinciples}
\end{table}

\end{document}

Which gives you slightly different output: