Environment fullwidthtabular

Implemented using xtab.sty
Might be necessary to provide proper definitions for proper multi-page tables

.latexmkrc

@@ -1,7 +1,7 @@
 # -*- mode: perl; -*-
 $pdf_mode = 4; # luaLaTeX
 $postscript_mode = $dvi_mode = 0;
-$lualatex = 'lualatex --synctex=8 --interaction batchmode --file-line-error --halt-on-error %O %S';
+$lualatex = 'lualatex --synctex=12 --interaction batchmode --file-line-error --halt-on-error %O %S';
 
 # cleanup temporary files from listings.sty / tcolorbox.sty
 push @generated_exts, 'listing';

sbabook.cls

@@ -1,5 +1,5 @@
 \NeedsTeXFormat{LaTeX2e}
-\ProvidesClass{sbabook}[2013/03/08]
+\ProvidesClass{sbabook}[2020/02/28]
 
 % \ExecuteOptions{a4paper,11pt,twoside}
 \ProcessOptions*
@@ -248,6 +248,11 @@
 \setfloatadjustment{figure}{\small\sffamily\centering}
 \setfloatadjustment{table} {\small\sffamily\centering}
 
+\usepackage{xtab}
+\newenvironment{fullwidthtabular}[1]{%
+    \begin{xtabular*}{\textwidth}{@{}#1@{}}%
+}{\end{xtabular*}}
+
 %%%
 %%% Graphics
 %%%

sbabook.tex

@@ -37,6 +37,7 @@
 \urlstyle{sf}
 \usepackage[unicode,breaklinks,hidelinks]{hyperref} % undecorated hyperlinks
 
+
 \title{the Square Bracket Associates\titlebreak{}
   \texorpdfstring{\protect\LaTeX}{LaTeX} book class}
 \author{Damien Pollet}
@@ -211,13 +212,13 @@ \section{Font choices}
 
 \begin{table}
   \caption{Fonts used in the document, and their roles}
-  \begin{tabular}{ll}
+  \begin{fullwidthtabular}{ll}
     \toprule
     \textnormal{Gentium -- \textit{Italic}} & Primary, paragraph text \\
     \textsf{Open Sans -- \textbf{Bold}}     & Structural and secondary text: titles, captions \\
     \texttt{Fira Mono}                      & Verbatim text and code \\
     \bottomrule
-  \end{tabular}
+  \end{fullwidthtabular}
   \label{tab:fontRoles}
 \end{table}
 
@@ -256,7 +257,7 @@ \section{Source code and listings}
 
 \begin{table}
   \caption{Some convenient delimiters for inline code}
-  \begin{tabular}{ll@{\qquad}ll}
+  \begin{fullwidthtabular}{ll@{\qquad}ll}
     \toprule
     \code_\code|...|_ & pipe                      & \code¶\code§...§¶ & section sign \\
     \code|\code_..._| & underscore                & \code§\code¶...¶§ & pilcrow      \\
@@ -265,7 +266,7 @@ \section{Source code and listings}
     \code¿\code?...?¿ & question mark             & \code`\code^...^` & circumflex   \\
     \code?\code¿...¿? & inverse question mark     & \code^\code`...`^ & backquote    \\
     \bottomrule
-  \end{tabular}
+  \end{fullwidthtabular}
   \label{tab:codeDelims}
 \end{table}
 

texlive-2018.deps

@@ -27,6 +27,7 @@ ulem
 varwidth
 xcolor
 xstring
+xtab
 
 ifetex
 luaotfload

texlive.deps

@@ -27,6 +27,7 @@ ulem
 varwidth
 xcolor
 xstring
+xtab
 
 fontaxes
 ragged2e