Multirow vertical positioning

Question

I can't specify the vertical position of my multirow content. The following compiles fine:

\documentclass{standalone}
\usepackage{booktabs,multirow}
\begin{document}
    \begin{tabular}{p{3cm}ccc}
        \toprule
        \multirow{2}{3cm}{Cat cat cat cat cat cat cat}
        &\multicolumn{3}{c}{Food}\\
        \cmidrule{2-4}
        & A&B&C\\
        \midrule
        D & 123 & 456 & 789\\\addlinespace
        E & 123 & 456 & 789\\\addlinespace
        F & 123 & 456 & 789\\
        \bottomrule
    \end{tabular}
\end{document}

But when I add [b] to the multirow it gets messed up:

\documentclass{standalone}
\usepackage{booktabs,multirow}
\begin{document}
    \begin{tabular}{p{3cm}ccc}
        \toprule
        \multirow[b]{2}{3cm}{Cat cat cat cat cat cat cat}
        &\multicolumn{3}{c}{Food}\\
        \cmidrule{2-4}
        & A&B&C\\
        \midrule
        D & 123 & 456 & 789\\\addlinespace
        E & 123 & 456 & 789\\\addlinespace
        F & 123 & 456 & 789\\
        \bottomrule
    \end{tabular}
\end{document}

According to the multirow documentation the syntax should be fine...

Answer 1

use of rules from booktabs add some vertical space which multirow can not compensate automatically for such and similar cases multirow has possibility to manual adjusting content position:

\documentclass[margin=3mm]{standalone}
\usepackage{booktabs,multirow}

\begin{document}
    \begin{tabular}{p{3cm}ccc}
        \toprule
        \multirow{2}{=}[-0.5ex]{Cat cat cat cat cat cat cat}% [-0.tex] is manual adjusting of posititon
          &   \multicolumn{3}{c}{Food}  \\
        \cmidrule{2-4}
          &  A  &  B  &   C             \\
        \midrule
        D & 123 & 456 & 789             \\\addlinespace
        E & 123 & 456 & 789             \\\addlinespace
        F & 123 & 456 & 789             \\
        \bottomrule
    \end{tabular}
\end{document}

Answer 2

The problem comes from the vertical padding around \cmidrule. You have to make a correction for this.

I propose another solution, just in case you don't really need a p column type; with the makecell package, you can break lines inside standard cells. I wrote a code that gives the same result with \multirowcell and a manual line-breaking:

\documentclass[border = 3pt]{standalone}
\usepackage{booktabs,multirow, makecell}

\begin{document}

\begin{tabular}{p{3cm}ccc}
  \toprule
  \multirow[b]{2}{3cm}[-\dimexpr\aboverulesep + \belowrulesep + \cmidrulewidth]{Cat cat cat cat cat cat cat}
    & \multicolumn{3}{c}{Food} \\
  \cmidrule{2-4}%
    & A & B & C \\
  \midrule
  D & 123 & 456 & 789 \\\addlinespace
  E & 123 & 456 & 789 \\\addlinespace
  F & 123 & 456 & 789 \\
  \bottomrule
\end{tabular}
\qquad\renewcommand\cellalign{bl}
\begin{tabular}{lccc}
  \toprule\
  \ & \multicolumn{3}{c}{Food} \\
  \cmidrule{2-4}%
  \multirowcell{-2}{Cat cat cat cat \\ cat cat cat} & A&B&C\\
  \midrule
  D & 123 & 456 & 789 \\\addlinespace
  E & 123 & 456 & 789 \\\addlinespace
  F & 123 & 456 & 789 \\
  \bottomrule
\end{tabular}

\end{document}