%%
%% The LaTeX Companion, 3ed
%%
%% Example A-4-2 on page II-675 in "Important generic hooks are available out of the box".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{135.0pt}

%StartShownPreambleCommands
\AddToHook{env/tabular/before}{\begin{center}}
\AddToHook{env/tabular/after}{\end{center}}
\AddToHook{env/tabular/begin}{\sffamily}

%StopShownPreambleCommands

\begin{document}
All tabulars are automatically centered and typeset in
Sans Serif \begin{tabular}{ll} a & b\\ c & d\end{tabular}
without explicitly adding \texttt{center} environments
or \verb=\sffamily=.
\end{document}