main.tex

\documentclass[margin=0.1cm]{standalone}
\usepackage{luacode} %improved lua code
\usepackage{pgfkeys}

\pgfkeys{%
    /tabular/.cd,%
    csv/.code={%
        \luaexec{dofile("script.lua")%
            csv_to_tabular(\luastring{#1})%
            tex.print("\string\\input{output.tex}\%")%
        }%
    },
    tsv/.code={%
        \directlua{dofile("script.lua")%
            tsv_to_tabular(\luastring{#1})%
            tex.print("\string\\input{output.tex}")%
        }%
    },
}

\newcommand{\tabularfromcsv}[2][csv]{
    \pgfkeys{/tabular/#1=#2}
}

\begin{document}

\begin{tabular}{c|c|c|c|c}%
\tabularfromcsv{test.csv}%
\end{tabular}

\begin{tabular}{c|c|c|c|c}
\input{output.tex}
\end{tabular}

\begin{tabular}{c|c|c|c|c}
01 & 02 & 03 & 04 & 05\\06 & 07 & 08 & 09 & 10\\11 & 12 & 13 & 14 & 15\\16 & 17 & 18 & 19 & 20\\21 & 22 & 23 & 24 & 26
\end{tabular}

\end{document}