The following MWE (Minimal Working Example) solve almost all your requirements :-)
\documentclass[conference]{IEEEtran}
\usepackage{subcaption}
\usepackage{booktabs, multirow}
\usepackage{siunitx}
%---------------- show page layout. don't use in a real document!
\usepackage{showframe}
\renewcommand\ShowFrameLinethickness{0.15pt}
\renewcommand*\ShowFrameColor{\color{red}}
%---------------------------------------------------------------%
\usepackage{lipsum}
\begin{document}
\lipsum[1]
\begin{table*}
% \caption{} % if you want to have a common caption of the table, remove %
% \label{tab:my-table} % remove % if you will use c+"\caption"
\begin{subfigure}{0.31\linewidth}
\centering % center table in "sibtable" environment
\caption{404-2} % caption of sub table
\label{subtab:my-table-a} % label for referencing od sub table
\begin{tabular}{*{4}{l}}
\toprule
& & \multicolumn{2}{l}{Predicted} \\
\cmidrule{3-4}
& & CR & NCR \\
\midrule
\multirow{2}{*}{something}
& CR & 340 & 22 \\
\cmidrule{2-4}
& NCR & 27 & 461 \\ \hline
Accuracy
& & \multicolumn{2}{l}{\SI{94.24}{\%}} \\
\midrule
MSE & & \multicolumn{2}{l}{0.11517} \\
\bottomrule
\end{tabular}
\end{subfigure}
\hfill % push subtables away
\begin{subfigure}{0.31\linewidth}
\centering
\caption{404-5-2}
\label{subtab:my-table-a}
\begin{tabular}{*{4}{l}}
\toprule
& & \multicolumn{2}{l}{Predicted} \\
\cmidrule{3-4}
& & CR & NCR \\
\midrule
\multirow{2}{*}{something}
& CR & 340 & 22 \\
\cmidrule{2-4}
& NCR & 27 & 461 \\ \hline
Accuracy
& & \multicolumn{2}{l}{\SI{94.24}{\%}} \\
\midrule
MSE & & \multicolumn{2}{l}{0.11517} \\
\bottomrule
\end{tabular}
\end{subfigure}%
\hfill
\begin{subfigure}{0.31\linewidth}
\centering
\caption{404-10-2}
\label{subtab:my-table-a}
\begin{tabular}{*{4}{l}}
\toprule
& & \multicolumn{2}{l}{Predicted} \\
\cmidrule{3-4}
& & CR & NCR \\
\midrule
\multirow{2}{*}{something}
& CR & 340 & 22 \\
\cmidrule{2-4}
& NCR & 27 & 461 \\ \hline
Accuracy
& & \multicolumn{2}{l}{\SI{94.24}{\%}} \\
\midrule
MSE & & \multicolumn{2}{l}{0.11517} \\
\bottomrule
\end{tabular}
\end{subfigure}
\bigskip % additiona vertical space between rows with subtables
\begin{subfigure}{0.31\linewidth}
\centering
\caption{210-2}
\label{subtab:my-table-a}
\begin{tabular}{*{4}{l}}
\toprule
& & \multicolumn{2}{l}{Predicted} \\
\cmidrule{3-4}
& & CR & NCR \\
\midrule
\multirow{2}{*}{something}
& CR & 340 & 22 \\
\cmidrule{2-4}
& NCR & 27 & 461 \\ \hline
Accuracy
& & \multicolumn{2}{l}{\SI{94.24}{\%}} \\
\midrule
MSE & & \multicolumn{2}{l}{0.11517} \\
\bottomrule
\end{tabular}
\end{subfigure}%
\hfill
\begin{subfigure}{0.31\linewidth}
\centering
\caption{210-5-2}
\label{subtab:my-table-a}
\begin{tabular}{*{4}{l}}
\toprule
& & \multicolumn{2}{l}{Predicted} \\
\cmidrule{3-4}
& & CR & NCR \\
\midrule
\multirow{2}{*}{something}
& CR & 340 & 22 \\
\cmidrule{2-4}
& NCR & 27 & 461 \\ \hline
Accuracy
& & \multicolumn{2}{l}{\SI{94.24}{\%}} \\
\midrule
MSE & & \multicolumn{2}{l}{0.11517} \\
\bottomrule
\end{tabular}
\end{subfigure}%
\hfill
\begin{subfigure}{0.31\linewidth}
\centering
\caption{210-10-2}
\label{subtab:my-table-a}
\begin{tabular}{*{4}{l}}
\toprule
& & \multicolumn{2}{l}{Predicted} \\
\cmidrule{3-4}
& & CR & NCR \\
\midrule
\multirow{2}{*}{something}
& CR & 340 & 22 \\
\cmidrule{2-4}
& NCR & 27 & 461 \\ \hline
Accuracy
& & \multicolumn{2}{l}{\SI{94.24}{\%}} \\
\midrule
MSE & & \multicolumn{2}{l}{0.11517} \\
\bottomrule
\end{tabular}
\end{subfigure}
\end{table*}
\lipsum\lipsum
\end{document}
Note: your table can not be fit in one column. Therefore i suggest to use table*
float environment. It is always on the top of the next page after point on insertion in document text.
addendum:
MWE according to your comment:
\documentclass[conference]{IEEEtran}
\usepackage{subcaption}
\usepackage{graphicx}
\usepackage{booktabs, multirow}
\usepackage{siunitx}
%---------------- show page layout. don't use in a real document!
\usepackage{showframe}
\renewcommand\ShowFrameLinethickness{0.15pt}
\renewcommand*\ShowFrameColor{\color{red}}
%---------------------------------------------------------------%
\usepackage{lipsum}
\begin{document}
\lipsum[1]
\begin{table*}
% \caption{}
% \label{tab:my-table}
\renewcommand\arraystretch{1.5}
\begin{subfigure}{0.31\linewidth}
\centering
\caption{404-2}
\label{subtab:my-table-a}
\begin{tabular}{cc|c|c}
\hline
& & \multicolumn{2}{l}{Predicted} \\
\cline{3-4}
& & CR & NCR \\
\hline
\multirow{2}{*}{\rotatebox{90}{something}}
\rule[-2ex]{0pt}{5ex}& CR & 340 & 22 \\
\cline{2-4}
\rule[-2ex]{0pt}{5ex}& NCR & 27 & 461 \\ \hline
\multicolumn{2}{l}{Accuracy}
& \multicolumn{2}{l}{\SI{94.24}{\%}} \\
\hline
\multicolumn{2}{l}{MSE}
& \multicolumn{2}{l}{0.11517} \\
\hline
\end{tabular}
\end{subfigure}%
\hfill
\begin{subfigure}{0.31\linewidth}
\centering
\caption{404-5-2}
\label{subtab:my-table-a}
\begin{tabular}{cc|c|c}
\hline
& & \multicolumn{2}{l}{Predicted} \\
\cline{3-4}
& & CR & NCR \\
\hline
\multirow{2}{*}{\rotatebox{90}{something}}
\rule[-2ex]{0pt}{5ex}& CR & 340 & 22 \\
\cline{2-4}
\rule[-2ex]{0pt}{5ex}& NCR & 27 & 461 \\ \hline
\multicolumn{2}{l}{Accuracy}
& \multicolumn{2}{l}{\SI{94.24}{\%}} \\
\hline
\multicolumn{2}{l}{MSE}
& \multicolumn{2}{l}{0.11517} \\
\hline
\end{tabular}
\end{subfigure}%
\hfill
\begin{subfigure}{0.31\linewidth}
\centering
\caption{404-10-2}
\label{subtab:my-table-a}
\begin{tabular}{cc|c|c}
\hline
& & \multicolumn{2}{l}{Predicted} \\
\cline{3-4}
& & CR & NCR \\
\hline
\multirow{2}{*}{\rotatebox{90}{something}}
\rule[-2ex]{0pt}{5ex}& CR & 340 & 22 \\
\cline{2-4}
\rule[-2ex]{0pt}{5ex}& NCR & 27 & 461 \\ \hline
\multicolumn{2}{l}{Accuracy}
& \multicolumn{2}{l}{\SI{94.24}{\%}} \\
\hline
\multicolumn{2}{l}{MSE}
& \multicolumn{2}{l}{0.11517} \\
\hline
\end{tabular}
\end{subfigure}
\bigskip
\begin{subfigure}{0.31\linewidth}
\centering
\caption{210-2}
\label{subtab:my-table-a}
\begin{tabular}{cc|c|c}
\hline
& & \multicolumn{2}{l}{Predicted} \\
\cline{3-4}
& & CR & NCR \\
\hline
\multirow{2}{*}{\rotatebox{90}{something}}
\rule[-2ex]{0pt}{5ex}& CR & 340 & 22 \\
\cline{2-4}
\rule[-2ex]{0pt}{5ex}& NCR & 27 & 461 \\ \hline
\multicolumn{2}{l}{Accuracy}
& \multicolumn{2}{l}{\SI{94.24}{\%}} \\
\hline
\multicolumn{2}{l}{MSE}
& \multicolumn{2}{l}{0.11517} \\
\hline
\end{tabular}
\end{subfigure}%
\hfill
\begin{subfigure}{0.31\linewidth}
\centering
\caption{210-5-2}
\label{subtab:my-table-a}
\begin{tabular}{cc|c|c}
\hline
& & \multicolumn{2}{l}{Predicted} \\
\cline{3-4}
& & CR & NCR \\
\hline
\multirow{2}{*}{\rotatebox{90}{something}}
\rule[-2ex]{0pt}{5ex}& CR & 340 & 22 \\
\cline{2-4}
\rule[-2ex]{0pt}{5ex}& NCR & 27 & 461 \\ \hline
\multicolumn{2}{l}{Accuracy}
& \multicolumn{2}{l}{\SI{94.24}{\%}} \\
\hline
\multicolumn{2}{l}{MSE}
& \multicolumn{2}{l}{0.11517} \\
\hline
\end{tabular}
\end{subfigure}%
\hfill
\begin{subfigure}{0.31\linewidth}
\centering
\caption{210-10-2}
\label{subtab:my-table-a}
\begin{tabular}{cc|c|c}
\hline
& & \multicolumn{2}{l}{Predicted} \\
\cline{3-4}
& & CR & NCR \\
\hline
\multirow{2}{*}{\rotatebox{90}{something}}
\rule[-2ex]{0pt}{5ex}& CR & 340 & 22 \\
\cline{2-4}
\rule[-2ex]{0pt}{5ex}& NCR & 27 & 461 \\ \hline
\multicolumn{2}{l}{Accuracy}
& \multicolumn{2}{l}{\SI{94.24}{\%}} \\
\hline
\multicolumn{2}{l}{MSE}
& \multicolumn{2}{l}{0.11517} \\
\hline
\end{tabular}
\end{subfigure}
\end{table*}
\lipsum\lipsum
\end{document}
edit:
- to the code of the fist MWE are added comments, which explain meaning of code parts responsible for caption and placement tables in
subtable
environmentand their placement in
table*` environment
- if you like to have table on the bottom of the same page (if there is enough space for table), than all what you need to do is:
- in preamble load the
stfloats
package by usepackage{stfloats}
- add placement option (
b
for bottomor
t` for the top of page):
\begin{table*}[b]
...
\end{table*}
for table on the bottom of a page or
\begin{tablee*}[t]
...
\end{table*}
for table on the top of a page.
table
float environment.