Table with text from side of page to the middle

Question

I would like to place a table from the side of the page to the middle with rounded corners. For example like this:

But I can't find anywhere how to do it. I can draw the image with Tikz but than I can'f fill it. I can draw a table with rounded corners around the text that goes in the table, but I can't place it just outside the margin.

EDIT The point of the document is to get two columns and some graphics between paragraphs. This questions is about the gray part at the bottom of the image. I would like the text in it with the same margin as the rest. But the grey color is perfect this way. All the text that is entered needs to be automatically returned to a new line. Additionally the second column needs to be at the same height as the OVerview chapter. I first made this with multicols but with that added the grey table could not be inserted.

And the code

\begin{document}

\basicPage

\productCode{Order code}
\topHeaderLine{
    Title row 1 \newline
    Title row 2
}

\makeHeader

\Large

\section{Overview}
\lipsum[1]

%\vbox{
\begin{table}[!ht]
    \begin{adjustwidth}{-2cm}{}
        \begin{tikzpicture}
        \node (table) [outer sep=5mm]   {
            \begin{tabular}{c}
            \Large
            text in row 1 but needs to be here      \\
            \Large
            text in row 2 but needs to be here      \\
            \Large
            text in row 3 but needs to be here      \\
            \Large
            text in row 4 but needs to be here      \\
            \Large
            text in row 5 but needs to be here          \\
            \Large
            text in row 6 but needs to be here          \\
            \Large
            text in row 7 but needs to be here          \\

            \end{tabular}
        };
        \scoped[on background layer]\fill[LightGrey,rounded corners=4mm] 
        (table.north west) -| (table.south east) -- (table.south west);
        \end{tikzpicture}

    \end{adjustwidth}
\end{table}

\vbox{
    \section{Applications}

    \begin{itemize}
        \item[$\bullet$] Point1.
        \item[$\bullet$] Point2.
        \item[$\bullet$] Point3.
        \item[$\bullet$] Point4.
        \item[$\bullet$] Point5.
    \end{itemize}
}


\section{Benefits}
\vbox{  
    \subsection{SubTitle}
    \lipsum[2]
}

Answer 1

As starting point:

\documentclass{article}
%\usepackage{tikz}
\usepackage{changepage}
\usepackage{calc}

\usepackage{lipsum}
\usepackage[showframe,
            margin=30mm]{geometry}

    \begin{document}
\lipsum[2]
    \begin{table}[!ht]
\begin{adjustwidth}{-\marginparwidth-2\marginparsep}{}
    \begin{tabular}{|c|c|c|}
    \hline
11111111111111  &   22222222222222  &   33333333333333     \\
    \hline 
    \end{tabular}
\end{adjustwidth}
    \end{table}
\lipsum[2]
\end{document}

for more, you need provide more data (actually you say in question that rounded corners and table is not the problem). Above MWE gives:

Addendum, that drawing of bacground of tables is the probelm (see comment of Alenanno), than see if the following suggestion lead to what you looking for:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{backgrounds, scopes}
\usepackage{changepage}
\usepackage{calc}

\usepackage{lipsum}
\usepackage[showframe,
            margin=30mm]{geometry}

    \begin{document}
\lipsum[2]
    \begin{table}[!ht]
\begin{adjustwidth}{-\marginparwidth-2\marginparsep}{}
    \begin{tikzpicture}
\node (table) [outer sep=2mm]   {
    \begin{tabular}{|c|c|c|}
    \hline
11111111111111  &   22222222222222  &   33333333333333     \\
    \hline 
    \end{tabular}
                };
\scoped[on background layer]\fill[gray!20,rounded corners=4mm] 
    (table.north west) -| (table.south east) -- (table.south west);
    \end{tikzpicture}

\end{adjustwidth}
    \end{table}
\lipsum[2]
\end{document}

which gives:

Above solution work fine in one side documents, for two side the solution is (far more) more complicated. If you have latter case, let me know.