I am trying to get the text below longtable to have the same spacing as normal tables (as you can see, as for my example, the spacing is quite big (due to the fact, I added it as multirow text?) (I am using LuaLatex btw in case that matters)
Is there a way to get it the same as normal tables?
%----------------------------------------------------------------------------
% LAYOUT
%----------------------------------------------------------------------------
\documentclass[
12pt,
a4paper,
headings=standardclasses,
listof=totoc,
numbers=noenddot
]{scrartcl}
\usepackage{showframe}
\usepackage[left=2.50cm, right=2.50cm, top=2.50cm, bottom=2.00cm, footskip=1cm]{geometry}
\usepackage[onehalfspacing]{setspace}
%----------------------------------------------------------------------------
% TABLES
%----------------------------------------------------------------------------
\usepackage{longtable}% longtables
\usepackage{array}
\newcolumntype{P}[1]{>{\raggedleft\arraybackslash}p{#1}}
\renewcommand{\arraystretch}{1.5}
\usepackage{subcaption,booktabs}
\usepackage{arydshln}% draw dash-lines in tables
\setlength\dashlinedash{0.2pt}
\setlength\dashlinegap{1.5pt}
\setlength\arrayrulewidth{0.3pt}
\usepackage{diagbox}% diagonal box
\usepackage{multirow}% multirow for diagonal box
\usepackage{tikz}% tikz
\usetikzlibrary{arrows.meta,decorations.pathmorphing,backgrounds,fit,positioning,shapes.symbols,chains}
%\usepackage{ltablex}
%\usepackage{pgfplotstable}
%----------------------------------------------------------------------------
% MAIN
%----------------------------------------------------------------------------
\begin{document}
\begin{table}[htb]
\caption{TableA}\label{ta:ta1}
\centering
\begin{tabular}[htb]{l}
\toprule
\textbf{TableA} \\
\midrule
a \\ \hdashline
b \\ \hdashline
c \\
\bottomrule
\end{tabular}
\\Quelle: Eigene Darstellung\\
\end{table}
\setlength{\extrarowheight}{0pt}
\addtolength{\extrarowheight}{\aboverulesep}
\addtolength{\extrarowheight}{\belowrulesep}
\setlength{\aboverulesep}{0pt}
\setlength{\belowrulesep}{0pt}
\ADLnullwidehline
\setlength\tabcolsep{2pt} % default: 6pt
\begin{longtable}{llp{3cm}l}
\caption{Übersicht des historischen Korpus (CHJ) von Chunagon}\label{ta:choverview}\\
\toprule
Epoche & Periode & Korpora & Einordnung \\
\midrule
\endhead
\bottomrule
\multicolumn{4}{p{\textwidth}}{\begin{center}Quelle: CHJ.2009\\
(Eigene Darstellung) \end{center}}
\endlastfoot
Altertum & Nara & Man’y\={o}sh\={u} & Gedicht- und Liederanthologie \\ \cdashline{3-4}
& & Norito & Ritualisierte shint\={o}. Gebete \\ \cdashline{3-4}
& & Senmy\={o} & Gesetzestexte \\ \cline{2-4}
& Heian & Monogatari & Fiktive Erzählung (Märchen) \\ \cdashline{3-4}
& & Nikki & Tagebuchliteratur \\ \hline
Mittelalter & Kamakura & Kaid\={o}ki & Reiseliteratur \\ \cdashline{3-4}
& & Nikki & Tagebuchliteratur \\ \cdashline{3-4}
& & Zuihitsu & Miszellenliteratur \\ \cline{2-4}
& Muromachi & Ky\={o}gen & Theater-Form \\ \cdashline{3-4}
& & Kirishitan Shiry\={o} & Christliche Literatur \\ \hline
Neuzeit & Edo & Kaid\={o}ki & Reiseliteratur \\ \cdashline{3-4}
& & Nikki & Tagebuchliteratur \\ \cdashline{3-4}
& & Zuihitsu & Miszellenliteratur \\ \cdashline{3-4}
& & Share-bon & Form der Komödie \\ \cdashline{3-4}
& & Ninj\={o}-bon & Romantische Literatur \\ \cline{2-4}
Moderne & \multirow{2}{*}{\begin{tabular}[c]{@{}l@{}}Meiji \&\\ Taishō\end{tabular}} & Zasshi & Zeitschriften \\ \cdashline{3-4}
& & Ky\={o}kasho & Schulbücher \\ \cdashline{3-4}
& & Meiji-shoki-k\={o}go Shiry\={o} & Sammlung gesprochener Sprache \\ \cdashline{3-4}
& & Kindai sh\={o}setsu & Moderne Romane \\
\end{longtable}
\end{document}
