% Rolf Niepraschk, 2023-07-15
%
% Translate to pdf with any TeX compiler and check the page size with
% 
%   pdfinfo filename.pdf
% 
% or via the properties menu of the pdf viewer
%
\listfiles
\documentclass[paper=a4,landscape]{scrartcl}
\usepackage{array}

% Just to show the page size of the source.
\usepackage{xcolor}
\AddToHook{shipout/background}{%
  \put(0,0){\textcolor{green!30}{\rule[-\paperheight]{\paperwidth}{\paperheight}}}%
}

\renewcommand\familydefault{\sfdefault}
\setlength\parindent{0pt}
\pagestyle{empty}

\usepackage{blowup}
\blowUp{target=a0,landscape,onepage}

\begin{document}

\null\vfill

\Large\centering

The first page of a multipage A4-size document scaled to \mbox{A0-size paper} 
(useful for poster)

\vfill

\setlength\extrarowheight{.5ex}
\begin{tabular}{|>{\bfseries}l<{:}r<{\,mm}!{$\times$}r<{\,mm}|} \hline
  letter    & 216 &  279 \\
  legal     & 216 &  356 \\
  executive & 184 &  267 \\
  A8        &  52 &   74 \\
  A7        &  74 &  105 \\
  A6        & 105 &  148 \\
  A5        & 148 &  210 \\
  A4        & 210 &  297 \\
  A3        & 297 &  420 \\
  A2        & 420 &  594 \\
  A1        & 594 &  841 \\
  A0        & 841 & 1189 \\ \hline
\end{tabular}

\vfill

\newpage\null 2nd page\,\dots

\end{document}