所以，这个例子让我很烦恼：
\documentclass[12pt,a4paper,twoside,DIV=9,BCOR=2cm,openright,parskip=never]{scrbook}
% \documentclass{article}
% \usepackage{floatrow}
\usepackage{subcaption}
% \setcapindent{0pt}
\usepackage{booktabs}
\usepackage{afterpage}
% \usepackage{pdflscape} % FOR DISPLAY
\usepackage{lscape} % FOR PRINTING
\usepackage{blindtext}
\begin{document}
\chapter{First chapter}
\blindtext
\begin{table}
\centering
\begin{tabular}{@{}cc@{}}
\toprule
10 & 20 \\ \midrule
30 & 40 \\
50 & 60 \\ \bottomrule
\end{tabular}
\caption{First table.}
\end{table}
\blindtext
\begin{landscape}
\begin{table}[p]
\centering
\caption{Summary of the answers to the demographics questionnaires}\label{tab:st3:demographics}
\subcaptionbox{A1: Have you studied music?}{
\begin{tabular}{@{}rccc}
\toprule
& {\bf\small no}
& {\bf\small informally}
& {\bf\small formally} \\ \midrule
{\bf\small beginners} & {\bf 7} & 5 & 2 \\
{\bf\small non-beginners} & 0 & 1 & {\bf 9} \\
{\bf\small total} & 7 & 6 & {\bf 11} \\ \bottomrule
\end{tabular}
}\qquad
\subcaptionbox{A2: Do you play a musical instrument?}{
\begin{tabular}{ccc}
\toprule
{\bf\small no}
& {\bf\small one}
& {\bf\small more} \\ \midrule
{\bf 10} & 3 & 1 \\
0 & 2 & {\bf 8} \\
{\bf 10} & 5 & 9 \\ \bottomrule
\end{tabular}
}\qquad
\subcaptionbox{A3: Have you ever composed original music?}{
\begin{tabular}{ccc}
\toprule
\textbf{\small never}
& \textbf{\small occasionally}
& \textbf{\small often} \\ \midrule
{\bf 11} & 3 & 0 \\
{\bf 4} & 2 & {\bf 4} \\
{\bf 15} & 5 & 4 \\ \bottomrule
\end{tabular}
}
\vspace{\baselineskip}
\subcaptionbox{A2.1: How would you rate your skills on your best instrument?}{
\begin{tabular}{@{}rccccc}
\toprule
& {\bf\small 1} & {\bf\small 2} & {\bf\small 3} & {\bf\small 4} & {\bf\small 5} \\ \midrule
{\bf\small beginners} & {\bf 4} & 1 & 1 & 0 & 0 \\
{\bf\small non-beginners} & 1 & 2 & {\bf 6} & 0 & 1 \\
{\bf\small total} & 5 & 3 & {\bf 7} & 0 & 1 \\ \bottomrule
\end{tabular}
}\qquad
\subcaptionbox{A3.1: How confident are you in your ability to compose original music?}{
\begin{tabular}{ccccc}
\toprule
{\bf\small 1} & {\bf\small 2} & {\bf\small 3} & {\bf\small 4} & {\bf\small 5} \\ \midrule
{\bf 8} & 5 & 1 & 0 & 0 \\
{\bf 3} & 2 & 2 & 2 & 1 \\
{\bf 11} & 7 & 3 & 2 & 1 \\ \bottomrule
\end{tabular}
}
\end{table}
\end{landscape}
\blindtext
\begin{table}
\centering
\begin{tabular}{@{}cc@{}}
\toprule
70 & 80 \\ \midrule
90 & 100 \\
110 & 120 \\ \bottomrule
\end{tabular}
\caption{Last table.}
\end{table}
\blindtext
\end{document}
“最后一张桌子”的编号应该是 1.3，但实际上它的编号是 1.4。我一时兴起，在命令\caption之前移动了这张大桌子\end{table}，然后突然就得到了“桌子 1.3。最后一张桌子”。
我的问题是：为什么？
更简单的例子（用于下面的评论）
\documentclass{scrbook}
\usepackage{subcaption}
\begin{document}
\chapter{First chapter}
x
\begin{table}
\centering
t1
\caption{First table.}
\end{table}
x
\begin{table}[p]
\caption{zz}
\subcaptionbox{A1}{???}
\end{table}
x
\begin{table}
\centering
t last
\caption{Last table.}
\end{table}
\end{document}
答案1
这里已经回答了这个问题：子表上方的标题与子标题包中断了下表的编号
\caption一些额外的背景知识：没有人阻止您在 中放置多个table。因此，subcaption包会考虑标题的位置。在您的例子中，您写道（启用 KOMA-Script 选项captions=tablesignature）：
\caption{zz}
\subcaptionbox{A1}{???}
这里发生了什么：\caption将增加table计数器。之后看到它前面\subcaptionbox有一个，并假设您正在环境中启动第二对内容+标题，因为您已经告诉 KOMA-Script 标题始终是排版的\captiontable后内容。因此它会增加table计数器。实际上，在这个例子中，您有两对内容+标题table：空内容+标题，以及\subcaptionbox没有额外标题的内容。如果 a\caption遵循此操作，则不会table再次增加计数器，因为第一个\subcaptionbox已经这样做了。自己尝试一下：
\documentclass{scrbook}
\usepackage{subcaption}
\begin{document}
\chapter{First chapter}
x
\begin{table}
\centering
t1
\caption{First table.}
\end{table}
x
\begin{table}[p]
\caption{zz}
\subcaptionbox{A1}{???}
\caption{zz} % This caption added, note that it does *not* increase the table counter
\end{table}
x
\begin{table}
\centering
t last
\caption{Last table.}
\end{table}
\end{document}
顺便说一句：为了调试子标题的计数器问题，最好将实际的图形/表格编号也放入子编号中：
\renewcommand\thesubfigure{\thefigure\alph{subfigure}}
\renewcommand\thesubtable{\thetable\alph{subtable}}这样，您就可以清楚地看到哪个命令实际上增加了数字和表格计数器。（如果您已完成调试，只需将这两行注释掉即可。）