A way to create a clear layout for large tables

Question

I know, that the question is somehow subjective, but this is my 2nd document writing in TeX. Therefore I've not so much input about the variety of commands and I would be very grateful for some ideas or commands to create table. My idea was to reduce the amount of horizontal lines and use some.

You can find below the mentioned table

\documentclass[a4paper]{scrartcl} 
\usepackage[ngerman]{babel}
\usepackage{amsthm}
\usepackage{mathtools}

\usepackage{rotating}
\usepackage{threeparttable}
\usepackage{booktabs}


\begin{document}
\begin{sidewaystable}
\centering
\begin{threeparttable}
\renewcommand*\TPTnoteLabel[1]{\parbox[b]{19pt}{\hfill#1}}
  \caption{Table} 
\begin{tabular}{@{\extracolsep{5pt}} cccccccccc} 
\toprule 
Sub 1 & Ml1. & Ml2. &  Ml3. &  Ml4. &  Ml5. &  Ml6. & Ml7. &  Ml8. \\ 
\midrule
$12.04.2010 - 07.03.2012$ & $0.6532$ & $0.4603\tnote{+}$ & $0.4635\tnote{+}$ & $0.4590\tnote{+}$ & $0.4586\tnote{+}$ & $0.4584\tnote{+}$ & $0.4601\tnote{+}$ & $0.4550\tnote{+}$ \\ 
$08.03.2012 - 04.02.2014$ & $0.6534$ & $0.4966\tnote{+}$ & $0.4747\tnote{+}$ & $0.4768\tnote{+}$ & $0.4764\tnote{+}$ & $0.4741\tnote{+}$ & $0.4737\tnote{+}$ & $0.4853\tnote{+}$ \\ 
$05.02.2014 -04.01.2016$  & $0.4913$ & $0.4443\tnote{+}$ & $0.4407\tnote{+}$ & $0.4321\tnote{+}$ & $0.4361\tnote{+}$ & $0.4298\tnote{+}$ & $0.4356\tnote{+}$ & $0.4531$ \\ 
$05.01.2016 - 04.12.2017$ & $0.4257$ & $0.3629\tnote{+}$ & $0.3515\tnote{+}$ & $0.3504\tnote{+}$ & $0.3849$ & $0.3572\tnote{+}$ & $0.3483\tnote{+}$ & $0.3646\tnote{+}$ \\
\hline \\[-1.8ex] 
Sub2 &  &  &  &  &  &  &  & \\ 
\hline \\[-1.8ex] 
$12.04.2010 - 07.03.2012$ & $0.3053$ & $0.2458\tnote{+}$ & $0.2457\tnote{+}$ & $0.2432\tnote{+}$ & $0.2435\tnote{+}$ & $0.2433\tnote{+}$ & $0.2435\tnote{+}$ & $0.2499\tnote{+}$ \\ 
$08.03.2012 - 04.02.2014$ & $0.2848$ & $0.2116\tnote{+}$ & $0.2071\tnote{+}$ & $0.2058\tnote{+}$ & $0.2096\tnote{+}$ & $0.2074\tnote{+}$ & $0.2064\tnote{+}$ & $0.2078\tnote{+}$ \\ 
$05.02.2014 -04.01.2016$  & $0.3423$ & $0.2698$ & $0.2596\tnote{+}$ & $0.2567\tnote{+}$ & $0.2569\tnote{+}$ & $0.2551\tnote{+}$ & $0.2561\tnote{+}$ & $0.2638\tnote{+}$ \\ 
$05.01.2016 - 04.12.2017$ & $0.2833$ & $0.2117$ & $0.2078\tnote{+}$ & $0.2049\tnote{+}$ & $0.2166$ & $0.2066\tnote{+}$ & $0.2051\tnote{+}$ & $0.2048\tnote{+}$ \\  
\hline \\[-1.8ex] 
Sub 3 &  &  &  &  &  &  &  & \\ 
\hline \\[-1.8ex] 
$12.04.2010 - 07.03.2012$ & $0.3462$ & $0.2927$ & $0.2839\tnote{+}$ & $0.2823\tnote{+}$ & $0.2867\tnote{+}$ & $0.2832\tnote{+}$ & $0.2831\tnote{+}$ & $0.2934\tnote{+}$ \\ 
$08.03.2012 - 04.02.2014$ & $0.3962$ & $0.3092\tnote{+}$ & $0.2994\tnote{+}$ & $0.2996\tnote{+}$ & $0.3023\tnote{+}$ & $0.3008\tnote{+}$ & $0.2991\tnote{+}$ & $0.3030\tnote{+}$ \\ 
$05.02.2014 -04.01.2016$ & $0.4278$ & $0.3706$ & $0.3530\tnote{+}$ & $0.3520\tnote{+}$ & $0.3583\tnote{+}$ & $0.3525\tnote{+}$ & $0.3545\tnote{+}$ & $0.3690$ \\ 
$05.01.2016 - 04.12.2017$ & $0.5177$ & $0.4090\tnote{+}$ & $0.4001\tnote{+}$ & $0.3996\tnote{+}$ & $0.4322$ & $0.4047\tnote{+}$ & $0.3964\tnote{+}$ & $0.4019\tnote{+}$ \\ 
\hline \\[-1.8ex] 
Sub 3 &  &  &  &  &  &  &  &  \\ 
\hline \\[-1.8ex] 
$12.04.2010 - 07.03.2012$ & $0.3716$ & $0.2819\tnote{+}$ & $0.2868\tnote{+}$ & $0.2800\tnote{+}$ & $0.2855\tnote{+}$ & $0.2832\tnote{+}$ & $0.2828\tnote{+}$ & $0.2841\tnote{+}$ \\ 
$08.03.2012 - 04.02.2014$ & $0.3508$ & $0.2644\tnote{+}$ & $0.2591\tnote{+}$ & $0.2563\tnote{+}$ & $0.2593\tnote{+}$ & $0.2558\tnote{+}$ & $0.2561$\tnote{+} & $0.2602\tnote{+}$ \\ 
$05.02.2014 -04.01.2016$ & $0.4661$ & $0.3565$ & $0.3422\tnote{+}$ & $0.3389\tnote{+}$ & $0.3366\tnote{+}$ & $0.3366\tnote{+}$ & $0.3372\tnote{+}$ & $0.3435\tnote{+}$ \\ 
$05.01.2016 - 04.12.2017$  & $0.4081$ & $0.2930$ & $0.2922\tnote{+}$ & $0.2875\tnote{+}$ & $0.3060$ & $0.2893\tnote{+}$ & $0.2880\tnote{+}$ & $0.2865\tnote{+}$ \\ 
\hline \\[-1.8ex] 
Sub 4 &  &  &  &  &  &  &  &  \\ 
\hline \\[-1.8ex] 
$12.04.2010 - 07.03.2012$ & $0.8119$ & $0.5476\tnote{+}$ & $0.5478\tnote{+}$ & $0.5422\tnote{+}$ & $0.5398\tnote{+}$ & $0.5410\tnote{+}$ & $0.5422\tnote{+}$ & $0.5388\tnote{+}$ \\ 
$08.03.2012 - 04.02.2014$ & $0.6772$ & $0.4893\tnote{+}$ & $0.4705\tnote{+}$ & $0.4723\tnote{+}$ & $0.4744\tnote{+}$ & $0.4719\tnote{+}$ & $0.4723\tnote{+}$ & $0.4788\tnote{+}$ \\ 
$05.02.2014 -04.01.2016$ & $0.6374$ & $0.5269\tnote{+}$ & $0.5299\tnote{+}$ & $0.5186\tnote{+}$ & $0.5223\tnote{+}$ & $0.5175\tnote{+}$ & $0.5224\tnote{+}$ & $0.5355\tnote{+}$ \\ 
$05.01.2016 - 04.12.2017$  & $0.4530$ & $0.3661$ & $0.3514$ & $0.3502$ & $0.3908$ & $0.3559$ & $0.3459\tnote{+}$ & $0.3625$ \\
\bottomrule
\end{tabular} 
\begin{tablenotes}
       \footnotesize
      \item Some notes.
    \end{tablenotes}
    \end{threeparttable}
\end{sidewaystable}

\end{document}

Answer 1

your table already look nice. i would not change much in it appearance. only should look if i can make table code slightly shorter ... :-). for example with use:

• for the first column would use >{$}c<{$}
• for other columns instead of c i would rather use S columns type determined by the package siunitx

• all horizontal lines should be from the ˙booktabs` package:

  \documentclass[a4paper]{scrartcl}
  \usepackage[ngerman]{babel}
  \usepackage{amsthm}
  \usepackage{mathtools}
  
  \usepackage{rotating}
  \usepackage{booktabs, threeparttable}
  \usepackage{siunitx}
  
  
  \begin{document}
  \begin{sidewaystable}
  \centering
  \begin{threeparttable}
    \caption{Table}
  \begin{tabular}{>{$}c<{$}
                  S[table-format=2.5]
             *{8}{S[table-format=1.4,
                    table-space-text-post={+}]}
                  }
      \toprule
  Sub 1 & {Ml1.} & {Ml2.} & {Ml3.} & {Ml4.} & {Ml5.} & {Ml6.} & {Ml7.} & {Ml8.} \\
      \midrule
  12.04.2010 - 07.03.2012
      & 0.6532 & 0.4603\tnote{+} & 0.4635\tnote{+} & 0.4590\tnote{+} & 0.4586\tnote{+} & 0.4584\tnote{+} & 0.4601\tnote{+} & 0.4550\tnote{+} \\
  08.03.2012 - 04.02.2014
      & 0.6534 & 0.4966\tnote{+} & 0.4747\tnote{+} & 0.4768\tnote{+} & 0.4764\tnote{+} & 0.4741\tnote{+} & 0.4737\tnote{+} & 0.4853\tnote{+} \\
  05.02.2014 -04.01.2016
      & 0.4913 & 0.4443\tnote{+} & 0.4407\tnote{+} & 0.4321\tnote{+} & 0.4361\tnote{+} & 0.4298\tnote{+} & 0.4356\tnote{+} & 0.4531 \\
  05.01.2016 - 04.12.2017
      & 0.4257 & 0.3629\tnote{+} & 0.3515\tnote{+} & 0.3504\tnote{+} & 0.3849 & 0.3572\tnote{+} & 0.3483\tnote{+} & 0.3646\tnote{+} \\
      \midrule
  Sub2 &  &  &  &  &  &  &  & \\
      \midrule
  12.04.2010 - 07.03.2012
      & 0.3053 & 0.2458\tnote{+} & 0.2457\tnote{+} & 0.2432\tnote{+} & 0.2435\tnote{+} & 0.2433\tnote{+} & 0.2435\tnote{+} & 0.2499\tnote{+} \\
  08.03.2012 - 04.02.2014
      & 0.2848 & 0.2116\tnote{+} & 0.2071\tnote{+} & 0.2058\tnote{+} & 0.2096\tnote{+} & 0.2074\tnote{+} & 0.2064\tnote{+} & 0.2078\tnote{+} \\
  05.02.2014 -04.01.2016
      & 0.3423 & 0.2698 & 0.2596\tnote{+} & 0.2567\tnote{+} & 0.2569\tnote{+} & 0.2551\tnote{+} & 0.2561\tnote{+} & 0.2638\tnote{+} \\
  05.01.2016 - 04.12.2017
      & 0.2833 & 0.2117 & 0.2078\tnote{+} & 0.2049\tnote{+} & 0.2166 & 0.2066\tnote{+} & 0.2051\tnote{+} & 0.2048\tnote{+} \\
      \midrule
  Sub 3 &  &  &  &  &  &  &  & \\
      \midrule
  12.04.2010 - 07.03.2012
      & 0.3462 & 0.2927 & 0.2839\tnote{+} & 0.2823\tnote{+} & 0.2867\tnote{+} & 0.2832\tnote{+} & 0.2831\tnote{+} & 0.2934\tnote{+} \\
  08.03.2012 - 04.02.2014
      & 0.3962 & 0.3092\tnote{+} & 0.2994\tnote{+} & 0.2996\tnote{+} & 0.3023\tnote{+} & 0.3008\tnote{+} & 0.2991\tnote{+} & 0.3030\tnote{+} \\
  05.02.2014 -04.01.2016
      & 0.4278 & 0.3706 & 0.3530\tnote{+} & 0.3520\tnote{+} & 0.3583\tnote{+} & 0.3525\tnote{+} & 0.3545\tnote{+} & 0.3690 \\
  05.01.2016 - 04.12.2017
      & 0.5177 & 0.4090\tnote{+} & 0.4001\tnote{+} & 0.3996\tnote{+} & 0.4322 & 0.4047\tnote{+} & 0.3964\tnote{+} & 0.4019\tnote{+} \\
      \midrule
  Sub 3 &  &  &  &  &  &  &  &  \\
      \midrule
  12.04.2010 - 07.03.2012
      & 0.3716 & 0.2819\tnote{+} & 0.2868\tnote{+} & 0.2800\tnote{+} & 0.2855\tnote{+} & 0.2832\tnote{+} & 0.2828\tnote{+} & 0.2841\tnote{+} \\
  08.03.2012 - 04.02.2014
      & 0.3508 & 0.2644\tnote{+} & 0.2591\tnote{+} & 0.2563\tnote{+} & 0.2593\tnote{+} & 0.2558\tnote{+} & 0.2561\tnote{+} & 0.2602\tnote{+} \\
  05.02.2014 -04.01.2016
      & 0.4661 & 0.3565 & 0.3422\tnote{+} & 0.3389\tnote{+} & 0.3366\tnote{+} & 0.3366\tnote{+} & 0.3372\tnote{+} & 0.3435\tnote{+} \\
  05.01.2016 - 04.12.2017
      & 0.4081 & 0.2930 & 0.2922\tnote{+} & 0.2875\tnote{+} & 0.3060 & 0.2893\tnote{+} & 0.2880\tnote{+} & 0.2865\tnote{+} \\
      \midrule
  Sub 4 &  &  &  &  &  &  &  &  \\
      \midrule
  12.04.2010 - 07.03.2012
      & 0.8119 & 0.5476\tnote{+} & 0.5478\tnote{+} & 0.5422\tnote{+} & 0.5398\tnote{+} & 0.5410\tnote{+} & 0.5422\tnote{+} & 0.5388\tnote{+} \\
  08.03.2012 - 04.02.2014
      & 0.6772 & 0.4893\tnote{+} & 0.4705\tnote{+} & 0.4723\tnote{+} & 0.4744\tnote{+} & 0.4719\tnote{+} & 0.4723\tnote{+} & 0.4788\tnote{+} \\
  05.02.2014 -04.01.2016
      & 0.6374 & 0.5269\tnote{+} & 0.5299\tnote{+} & 0.5186\tnote{+} & 0.5223\tnote{+} & 0.5175\tnote{+} & 0.5224\tnote{+} & 0.5355\tnote{+} \\
  05.01.2016 - 04.12.2017
      & 0.4530 & 0.3661 & 0.3514 & 0.3502 & 0.3908 & 0.3559 & 0.3459\tnote{+} & 0.3625 \\
      \bottomrule
  \end{tabular}
  \begin{tablenotes}[flushleft]\footnotesize
        \item[+] Some notes.
      \end{tablenotes}
      \end{threeparttable}
  \end{sidewaystable}
  \end{document}