我看到有人回答了这个问题。显然你需要使用 \xtab，但我不知道如何将它适配到这个长表。我基本上希望表格在每一页上尽可能居中。谢谢。
\documentclass[A4paper, 10pt, openany, draft]{book}
%PACKAGES
\usepackage{fontspec}
\usepackage{libertine}
\usepackage{titlesec}
\usepackage{multicol}
\usepackage{fancyhdr}
\usepackage{enumitem}
\usepackage{longtable}
%\usepackage{layout}
\usepackage{tikz}
\usepackage{eso-pic}
\usepackage{hyphenat}
\usepackage[paperwidth=5.83in, paperheight=8.27in, bindingoffset=.625in]{geometry}
\pagestyle{fancy}
\fancypagestyle{firststyle}{\fancyhead{}\fancyfoot[CE,CO]{\thepage}}
\begin{document}
\titleformat{\chapter}[display]{\normalfont\bfseries\centering\Large}{}{0pt}{}
\titleformat{\section}[display]{\normalfont\itshape\centering}{}{0pt}{}
\chapter{Chapter Title}
\fancyhf{}
\fancyfoot[CE,CO]{\thepage}
\fancyhead[CO,CE]{\textsc{First List}}
\thispagestyle{firststyle}
\setlength\LTleft{\fill}
\setlength\LTright{\fill}
\begin{longtable}{r l}
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
1: & desc 1\\
7: & descriptiondescription 4325985\\
7: & descriptiondescription 4325985\\
7: & descriptiondescription 4325985\\
7: & descriptiondescription 4325985\\
\end{longtable}
\end{document}