How to increase space between tabulars inside a table

Question

I have a table with six tabular inside. They all belong to one problem and caption.

I positioned them with \hfill, which works ok, but there could be more space between the two rows of tabular. \hspace did not work.

How can I increase the space?

Here is my TeX

\documentclass{scrartcl}
\usepackage{float}
\usepackage[a4paper, top=3cm,bottom=3cm,left=2.5cm,right=2cm]{geometry} 
\usepackage{bm}
\begin{document}

\begin{table}[H]
    \centering
    \begin{tabular}{c|cccc}
      \bm{$K_0$} & $Q_0$ & $Q_0$ & $\bar Q_0$ & $\bar Q_0$ \\
      \hline
      $Q_1$      & X & 1 & X & X \\
      $\bar Q_1$ & 1 & 1 & X & X \\
      \hline
      & $Q_2$ & $\bar Q_2$ & $\bar Q_2$ & $ Q_2$ 
    \end{tabular}
    \hfill
    \begin{tabular}{c|cccc}
      \bm{$J_0$} & $Q_0$ & $Q_0$ & $\bar Q_0$ & $\bar Q_0$ \\
      \hline
      $Q_1$      & X & X & 1 & 0 \\
      $\bar Q_1$ & X & X & 1 & 1 \\
      \hline
      & $Q_2$ & $\bar Q_2$ & $\bar Q_2$ & $ Q_2$ 
    \end{tabular}
    \hfill
    \begin{tabular}{c|cccc}
      \bm{$K_1$}  & $Q_0$ & $Q_0$ & $\bar Q_0$ & $\bar Q_0$ \\
      \hline
      $Q_1$      & X & 1 & 0 & 1 \\
      $\bar Q_1$ & X & X & X & X \\
      \hline
      & $Q_2$ & $\bar Q_2$ & $\bar Q_2$ & $ Q_2$ 
    \end{tabular}
    \hfill
    \begin{tabular}{c|cccc}
      \bm{$J_1$}  & $Q_0$ & $Q_0$ & $\bar Q_0$ & $\bar Q_0$ \\
      \hline
      $Q_1$      & X & X & X & X \\
      $\bar Q_1$ & 1 & 1 & 0 & X \\
      \hline
      & $Q_2$ & $\bar Q_2$ & $\bar Q_2$ & $ Q_2$ 
    \end{tabular}
    \hfill
    \begin{tabular}{c|cccc}
      \bm{$K_2$}  & $Q_0$ & $Q_0$ & $\bar Q_0$ & $\bar Q_0$ \\
      \hline
      $Q_1$      & X & X & X & 1 \\
      $\bar Q_1$ & 0 & X & 0 & X \\
      \hline
      & $Q_2$ & $\bar Q_2$ & $\bar Q_2$ & $ Q_2$ 
    \end{tabular}
    \hfill
    \begin{tabular}{c|cccc}
      \bm{$J_2$}  & $Q_0$ & $Q_0$ & $\bar Q_0$ & $\bar Q_0$ \\
      \hline
      $Q_1$      & X & 1 & X & X \\
      $\bar Q_1$ & X & X & 0 & X \\
      \hline
      & $Q_2$ & $\bar Q_2$ & $\bar Q_2$ & $ Q_2$ 
    \end{tabular}
    \hfill
    \caption{Caption}
    \label{tab:my_label}
\end{table}
\end{document}

This is what it looks like

Answer 1

(re-posting my earlier comment as an answer, so that this query can be considered to have received an "official" answer).

To achieve your formatting objective, you should replace the third \hfill directive with an all-blank line (to induce a paragraph break) followed by \bigskip before the next instance of \begin{tabular}.

Some additional comments: (i) You may (actually, should) omit the \centering directive as it doesn't do anything in the your setup. (ii) The sixth and final \hfill directive should be deleted (or commented out). (iii) \bm (short for "bold math") should be employed only in math mode; hence, do replace \bm{$K_0$} with $\bm{K_0}$, \bm{$J_0$} with $\bm{J_0}$, etc. (iv) Using [H] to force the placement of the table "right here, damn it!" can actually be counterproductive; use [ht!] instead.

\documentclass{scrartcl}
\usepackage{float}
\usepackage[a4paper, vmargin=3cm, left=2.5cm, right=2cm]{geometry} 
\usepackage{bm}
\begin{document}

\begin{table}[H]
    %\centering % <-- not needed
    \begin{tabular}{c|cccc}
      $\bm{K_0}$ & $Q_0$ & $Q_0$ & $\bar Q_0$ & $\bar Q_0$ \\
      \hline
      $Q_1$      & X & 1 & X & X \\
      $\bar Q_1$ & 1 & 1 & X & X \\
      \hline
      & $Q_2$ & $\bar Q_2$ & $\bar Q_2$ & $ Q_2$ 
    \end{tabular}
    \hfill
    \begin{tabular}{c|cccc}
      $\bm{J_0}$ & $Q_0$ & $Q_0$ & $\bar Q_0$ & $\bar Q_0$ \\
      \hline
      $Q_1$      & X & X & 1 & 0 \\
      $\bar Q_1$ & X & X & 1 & 1 \\
      \hline
      & $Q_2$ & $\bar Q_2$ & $\bar Q_2$ & $ Q_2$ 
    \end{tabular}
    \hfill
    \begin{tabular}{c|cccc}
      $\bm{K_1}$  & $Q_0$ & $Q_0$ & $\bar Q_0$ & $\bar Q_0$ \\
      \hline
      $Q_1$      & X & 1 & 0 & 1 \\
      $\bar Q_1$ & X & X & X & X \\
      \hline
      & $Q_2$ & $\bar Q_2$ & $\bar Q_2$ & $ Q_2$ 
    \end{tabular}

    \bigskip % <-- new, in lieu of \hfill
    \begin{tabular}{c|cccc}
      $\bm{J_1}$  & $Q_0$ & $Q_0$ & $\bar Q_0$ & $\bar Q_0$ \\
      \hline
      $Q_1$      & X & X & X & X \\
      $\bar Q_1$ & 1 & 1 & 0 & X \\
      \hline
      & $Q_2$ & $\bar Q_2$ & $\bar Q_2$ & $ Q_2$ 
    \end{tabular}
    \hfill
    \begin{tabular}{c|cccc}
      $\bm{K_2}$  & $Q_0$ & $Q_0$ & $\bar Q_0$ & $\bar Q_0$ \\
      \hline
      $Q_1$      & X & X & X & 1 \\
      $\bar Q_1$ & 0 & X & 0 & X \\
      \hline
      & $Q_2$ & $\bar Q_2$ & $\bar Q_2$ & $ Q_2$ 
    \end{tabular}
    \hfill
    \begin{tabular}{c|cccc}
      $\bm{J_2}$  & $Q_0$ & $Q_0$ & $\bar Q_0$ & $\bar Q_0$ \\
      \hline
      $Q_1$      & X & 1 & X & X \\
      $\bar Q_1$ & X & X & 0 & X \\
      \hline 
      & $Q_2$ & $\bar Q_2$ & $\bar Q_2$ & $ Q_2$ 
    \end{tabular}
    %\hfill % <-- not needed either
    \caption{Caption}
    \label{tab:my_label}
\end{table}
\end{document}