Arrange Bibliography in table

Question

I am using the code as suggested by Audrey in this post in order to produce a tabular bibliography and adapted it as follows.

Naturally, the authors' names should be printed in the first column and everything else in the second, yet the names are repeated in the second column. The second modification that I wish to make, is to add some text between the heading and the table.

\documentclass[12pt,a4paper,oneside]{memoir}
\usepackage[backend=biber,style=biblatex-swiss-legal-general]{biblatex}
\usepackage{etoolbox}
\usepackage{chngcntr}
\usepackage{csquotes}
\usepackage{array}
\usepackage{ragged2e}
\newcolumntype{P}[1]{>{\raggedright\hspace{0pt}}p{#1}}
\usepackage{multicol}
\usepackage{etoolbox}

\renewcommand{\mkbibnamefirst}[1]{\textsc{#1}}
\renewcommand{\mkbibnamelast}[1]{\textsc{#1}}
\renewcommand{\mkbibnameprefix}[1]{\textsc{#1}}
\renewcommand{\mkbibnameaffix}[1]{\textsc{#1}}

\makeatletter

% user-level command for printing tabular bibliography
\let\printbibtabular\printbibliography
\patchcmd{\printbibtabular}{\blx@printbibliography}{\bbx@printbibtabular}{}{}
\patchcmd{\printbibtabular}{\blx@printbibliography}{\bbx@printbibtabular}{}{}
\let\bbx@printbibtabular\blx@printbibliography
\patchcmd{\bbx@printbibtabular}{\blx@bibliography}{\bbx@bibtabular}{}{}
\patchcmd{\bbx@printbibtabular}
  {\def\blx@theenv{bibliography}}{\def\blx@theenv{bibtabular}}{}{}

% underlying macros
\def\bbx@bibtabular#1{%
  \blx@bibheading\blx@theheading\blx@thetitle
  \blx@bibnote\blx@theprenote
  \begingroup
  \blx@bibinit
  \let\@noitemerr\@empty
  \let\blx@noitem\blx@warn@bibempty
  \ifnum\bibinitsep=\z@
    \let\blx@initsep\relax
  \fi
  \ifnum\bibnamesep=\z@
    \let\blx@namesep\relax
  \fi
  \csuse{blx@hook@bibinit}%

  % copy filtered list of entries to internal list macro
  \def\blx@do##1{%
    \blx@ifdata{##1}{%
      \begingroup
      \blx@getdata{##1}
      \blx@bibcheck
      \iftoggle{blx@skipentry}{}{%
        \global\let\blx@noitem\@empty
        \listadd\blx@tempa{##1}}%
      \endgroup}{}}
  \let\blx@done\relax
  \blx@listloop{#1}

  % tabular output for each item in list macro
  \def\do##1{\bbx@tab@label{##1} & \bbx@tab@item{##1} \\}
  \def\do##1{\bbx@tab@label{##1} & \bbx@tab@item{##1} \\}
  \csuse{blx@env@\blx@theenv}%
  \dolistloop{\blx@tempa}
  \csuse{blx@endenv@\blx@theenv}%
  \blx@bibnote\blx@thepostnote
  \endgroup}

\def\bbx@tab@label#1{%
  \begingroup
  \blx@getdata{#1}%
  \blx@setoptions@type\abx@field@entrytype
  \blx@setoptions@entry
  \blx@thelabelnumber
  \blx@addprefixnumber
  \addtocounter{instcount}\@ne
  \csuse{bbx@tabenv@\blx@theenv}\relax
  \endgroup}

\def\bbx@tab@item#1{%
  \begingroup
  \blx@getdata{#1}%
  \blx@setoptions@type\abx@field@entrytype
  \blx@setoptions@entry
  \csuse{blx@item@\blx@theenv}\relax
  \blx@initsep
  \blx@namesep
  \csuse{blx@hook@bibitem}%
  \blx@execute
  \blx@initunit
  \blx@anchor
  \blx@beglang
  \bibsentence
  \blx@pagetracker
  \blx@driver\abx@field@entrytype
  \blx@postpunct
  \blx@endlang
  \endgroup}

% user-level command for defining tabular bibliography format
\newrobustcmd*{\defbibtabular}[5]{%
  \long\csdef{blx@env@#1}{#2}%
  \long\csdef{blx@endenv@#1}{#3}%
  \long\csdef{bbx@tabenv@#1}{#4}%
  \long\csdef{blx@item@#1}{#5}}

% user-level access to some entry options
\def\useeditorfalse{\togglefalse{blx@useeditor}}
\def\usetranslatorfalse{\togglefalse{blx@usetranslator}}

\makeatother

% sortname labels (a robust style should add provision for missing labelnames)
\newbibmacro*{sortname}{%
  \renewcommand*{\multinamedelim}{\addslash\break}%
  \let\finalnamedelim\multinamedelim
  \printtext{\printnames[last-first]{labelname}}}

% bibitem hook to suppress redundant sortname list
\newbibmacro*{omitsortname}{%
  \ifnameundef{labelname}{}{%
    \ifnameundef{author}
      {\ifnameundef{editor}
         {\ifusetranslator{\clearname{translator}}{}}}
         {\clearname{editor}}
      {\clearname{author}}%
    \useeditorfalse%
    \usetranslatorfalse}}

% demo new tabular bibliography format
\defbibtabular{bibtabular}
 {\setlength{\tabcolsep}{8pt}\begin{tabular}{@{}P{5.5cm} >{\raggedright\arraybackslash}p{9cm}}}
 {\end{tabular}}
 {\usebibmacro{sortname}}
 {\usebibmacro{omitsortname}}

% add multiline labels in default bibliography format
\defbibenvironment{bibliography}
  {\list
     {\usebibmacro{sortname}}
     {\setlength{\labelwidth}{0.3\textwidth}%
      \setlength{\leftmargin}{\labelwidth}%
      \setlength{\labelsep}{\biblabelsep}%
      \addtolength{\leftmargin}{\labelsep}%
      \setlength{\itemsep}{\bibitemsep}%
      \setlength{\parsep}{\bibparsep}}%
     \renewcommand*{\makelabel}[1]{%
       \nobreak\strut\smash{\parbox[t]\labelwidth{\raggedright##1}}}}
  {\endlist}
  {\item\usebibmacro{omitsortname}}

\addbibresource{biblatex-examples.bib}

\renewcommand{\cmd}[1]{\texttt{\textbackslash #1}}

\begin{document}

\printbibtabular

\cite{vangennep:trans,companion,bertram}

\end{document}

Thank you for your help.