Create environment that allows writing multi-page table content down the column rather than across the row

Question

A description of the behavior I would like:

I have a very long list of procedural steps. Each step must have an image and a block of text. Since each step only really needs the half the width of a landscape page, my initial thought was to place this list of steps in a five-column table, where:

• Step 1 is placed in row 1, columns 1-2 of the five-column table
• Step 2 is placed in row 2, columns 1-2 of the five-column table
• ...
• Step 5 is placed in row 1, column 4-5 of the five-column table
• Step 6 is placed in row 2, column 4-5 of the five-column table

until the table fills the page (column 3 of the five-column table is simply used to add space between columns 2 and 4). So far, I have this behavior working.

Now, I would like for this table to be able to span multiple pages, and in doing so, the table described above continues with:

• Step 7 is placed in row 1, columns 1-2 of a five-column table, on the second page
• Step 8 is placed in row 2, columns 1-2 of a five-column table, on the second page
• ...
• Step 12 is placed in row 1, columns 4-5 of a five-column table, on the second page
• Step 13 is placed in row 2, columns 4-5 of a five-column table, on the second page

and so on for as many pages as needed. There should also be some space at the footer of each page allowing for some brief notes about a given step that appears on that page.

A description of some constraints on the way I would like to input this in the source file:

Since I am using enumerate to number the steps, I would like to write the entire content sequentially in the source file, such that they will appear "snaking" across multiple pages, as described above, in the output. Otherwise, I end up needing multiple \begin{enumerate} ... \end{enumerate} sections, and having to pre-calculate what item numbers to begin with in the last column for every page (i.e. 5 and 12 in the above description), and this becomes extremely tedious when considering many tables, and lots of content to keep updating/replacing.

Can someone help me create an environment that will allow me to make this content, given the above descriptions?

A single page I created to illustrate what one page might look like:

(but here I am still using multiple \begin{enumerate} ... \end{enumerate} sections which is undesirable)

\documentclass[12pt]{article}
\usepackage{longtable}
\usepackage{lipsum}
\usepackage{todonotes}
\usepackage{pdflscape}
\usepackage{tabu}
\usepackage{fancyhdr}

\topmargin -2cm
\oddsidemargin -0.7cm
\textwidth 18 cm 
\textheight 24cm
\footskip 1.0cm
\pagestyle{fancy}
\fancyhf{}

\begin{document}
\begin{landscape}
\subsubsection{some section name here} \label{somesection}
\thispagestyle{empty}
\begin{center}
\begin{tabular}{| m{2in} | m{2.2in} | m{0.01\textwidth} | m{2in} | m{2.2in} |}
\missingfigure[figwidth=2in]{} & 
\begin{enumerate}
\item hi
\end{enumerate}
& & \missingfigure[figwidth=2in]{} & 
\begin{enumerate}
\addtocounter{enumi}{4}
\item  hi
\end{enumerate}
\\  [4pt]
\missingfigure[figwidth=2in]{} & 
\begin{enumerate}
\addtocounter{enumi}{1}
\item bla
\item bla
\end{enumerate}
& & \missingfigure[figwidth=2in]{} & 
\begin{enumerate}
\addtocounter{enumi}{5}
\item hi
\end{enumerate}
\\  [4pt]
\missingfigure[figwidth=2in]{} & 
\begin{enumerate}
\addtocounter{enumi}{3}
\item hi
\end{enumerate}
& & \missingfigure[figwidth=2in]{} &
\begin{enumerate}
\addtocounter{enumi}{6}
\item $\dagger$~hi
\item hi
\end{enumerate}
 \\  [4pt]
\end{tabular}
\end{center}
\vspace{0.2in}
$\dagger$~~hello there, some notes here about step 7
\end{landscape}
\end{document}

If this list of steps had more then 8 steps, then the page after this would look very similar, but would not have a section name, would begin with 9 instead of 1, and would proceed down columns 1-2 first, then down columns 4-5.

Answer 1

I think you are looking for something like

\documentclass[12pt]{article}
\usepackage{longtable}
\usepackage{lipsum}
\usepackage{todonotes}
\usepackage{pdflscape}
\usepackage{tabu}
\usepackage{fancyhdr}
\usepackage{multicol}
\usepackage{enumitem}
\topmargin -2cm
\oddsidemargin -0.7cm
\textwidth 18 cm 
\textheight 24cm
\footskip 1.0cm
\pagestyle{fancy}
\fancyhf{}

\begin{document}
\begin{landscape}
\begin{multicols}{2}
\subsubsection{some section name here} \label{somesection}
\thispagestyle{empty}
\raggedright

\raisebox{-.8\height}{\missingfigure[figwidth=2in]{}}\hfill
\begin{minipage}[t]{\dimexpr\columnwidth-2.2in\relax}
\begin{enumerate}[series=zz]
\item hi
\end{enumerate}
\end{minipage}

\raisebox{-.8\height}{\missingfigure[figwidth=2in]{}}\hfill
\begin{minipage}[t]{\dimexpr\columnwidth-2.2in\relax}
\begin{enumerate}[resume=zz]
\item bla
\item bla
\end{enumerate}
\end{minipage}

\raisebox{-.8\height}{\missingfigure[figwidth=2in]{}}\hfill
\begin{minipage}[t]{\dimexpr\columnwidth-2.2in\relax}
\begin{enumerate}[resume=zz]
\item hi
\end{enumerate}
\end{minipage}


\raisebox{-.8\height}{\missingfigure[figwidth=2in]{}}\hfill
\begin{minipage}[t]{\dimexpr\columnwidth-2.2in\relax}
\begin{enumerate}[resume=zz]
\item hi
\end{enumerate}
\end{minipage}

\raisebox{-.8\height}{\missingfigure[figwidth=2in]{}}\hfill
\begin{minipage}[t]{\dimexpr\columnwidth-2.2in\relax}
\begin{enumerate}[resume=zz]
\item $\dagger$~hi
\item hi
\end{enumerate}
\end{minipage}

\bigskip

$\dagger$~~hello there, some notes here about step 7
\end{multicols}
\end{landscape}
\end{document}