Left align table to margin with newcolumntype

Question

I am trying to make simple tables that span the width of my body text with the \newcolumntype command in LaTeX.

In the left column, I would like the text to be right-aligned (within the column). However, I'd like the left-hand side of this column to align with my left margin.

In the right column, I'd like the text to be left-aligned, and continue until it reaches the right margin.

I'd like there to be a small bit of padding between the two columns.

My current code is as follows:

\newcolumntype{L}{>{\raggedleft}p{0.2\textwidth}}
\newcolumntype{R}{p{0.7\textwidth}}

Tables are:

\begin{tabular}{L!{}R}
...
\end{tabular}

The problem I am having is that the left-hand column will not align with my left margin in my document. Instead, it severely indents. I cannot figure out how to fix it. Any advice is greatly appreciated!

Answer 1

I suggest you employ a tabular* rather than a tabular environment and set the overall width of the tabular* environment to \textwidth.

Since you wrote, "In the right column, I'd like the text to be left-aligned", I think the column definition should be

\newcolumntype{R}{>{\raggedright}p{0.7\textwidth}}

rather than just

\newcolumntype{R}{p{0.7\textwidth}}

And do insert the instruction \noindent right before \begin{tabular*}.

The framelines in the following screenshot are drawn because the showframe package is loaded in the underlying brief test document.

\documentclass{article}
\usepackage{array,showframe,lipsum}
\newcolumntype{L}{>{\raggedleft} p{0.225\textwidth}}
\newcolumntype{R}{>{\raggedright}p{0.725\textwidth}}
\begin{document}

\noindent% <-- very important
\begin{tabular*}{\textwidth}{@{\extracolsep{\fill}} LR @{}}
\lipsum[1][2-4] & \lipsum[2]  \\
\end{tabular*}

\end{document}

---

Addendum: Here's how you might achieve the same outcome while using a longtable environment instead of a tabular* environment. (I'm not posting a second screenshot, as it would be identical to the one shown above.)

\setlength\LTleft{0pt}
\setlength\LTright{0pt}
\begin{longtable}{@{\extracolsep{\fill}} LR @{}}
\lipsum[1][2-4] & \lipsum[2]  \\
\end{longtable}