LaTeX - datatool creating a matrix with 3x3 data \ DTLforeach

I am using datatool package. Several csv files with data are generated in my project and I create index.csv to use Nested \ DTLforeach.

I do not understand how I can assemble a 3x3 / 3x4 or 3x5 matrix depending on the number of csv files.

\documentclass[a4paper]{article}
\usepackage{pgf}
\usepackage{pgffor}
\usepackage{datatool}


\begin{document}
\begin{filecontents}{index.csv}
    File
    1.csv
    2.csv
    3.csv
    4.csv
    5.csv
    6.csv
    7.csv
\end{filecontents}
\begin{filecontents}{1.csv}
    Header 1
    image 1
    description 1
\end{filecontents}
\begin{filecontents}{2.csv}
    Header 2
    image 2
    description 2
\end{filecontents}
\begin{filecontents}{3.csv}
    Header 3
    image 3
    description 3
\end{filecontents}
\begin{filecontents}{4.csv}
    Header 4
    image 4
    description 4
\end{filecontents}
\begin{filecontents}{5.csv}
    Header 5
    image 5
    description 5
\end{filecontents}
\begin{filecontents}{6.csv}
    Header 6
    image 6
    description 6
\end{filecontents}
\begin{filecontents}{7.csv}
    Header 7
    image 7
    description 7
\end{filecontents}

\begin{tabular}{p{86pt} p{86pt} p{86pt}}
\hline

\DTLloaddb{index}{index.csv}
\DTLforeach{index}{\theFile=File}{
\DTLloaddb{\theFile}{\theFile}
\DTLforeach{\theFile}{\theHeader=\theFile}{\theHeader & \theHeader & \theHeader \\}
} 


\end{tabular}
\end{document}

How can a matrix be formed so that it detects the heading of each csv file and substitutes it in the tabular environment. I have no idea how to achieve this result, thank you for any help.