I have a table float with four subtables and having trouble with alignment and placing. Here's the code:
\begin{table}
\begin{subtable}{0.45\textwidth}
\centering
\begin{tabular}[t]{cccc}
\toprule
Band & L & $\mathcal{O}_{JK}^2$ & $\mathcal{O}_{EP}^2$ \\
\midrule
1 & 0 & 0.97470(3) & 0.9881(3) \\
\midrule
& 2 & 0.8290(2) & 0.882(2) \\
& 3 & 0.96595(4) & 0.979(1) \\
2 & 4 & 0.95328(6) & 0.9736(8) \\
& 5 & 0.98727(2) & 0.9950(10) \\
& 6 & 0.9168(1) & 0.950(1) \\
\midrule
& 0 & 0.7776(4) & 0.8685(8) \\
& 1 & 0.96289(5) & 0.971(2) \\
& 2 & 0.8385(2) & 0.8838(8) \\
& 3 & 0.9021(1) & 0.929(1) \\
& 4 & 0.8687(2) & 0.9079(7) \\
3 & 5 & 0.9382(1) & 0.946(3) \\
& 6 & 0.9052(2) & 0.9401(4) \\
& 7 & 0.9198(2) & 0.9483(5) \\
& 8 & 0.9649(5) & 0.9763(4) \\
& 9 & 0.9502(1) & 0.971(2) \\
& 10 & 0.9126(3) & 0.941(2) \\
\bottomrule
\end{tabular}
\caption{\footnotesize (10,15)}
\label{tab:table1_a}
\end{subtable}%
\begin{subtable}{0.45\textwidth}
\centering
\begin{tabular}[t]{cccc}
\toprule
Band & L & $\mathcal{O}_{JK}^2$ & $\mathcal{O}_{EP}^2$ \\
\midrule
1 & 0 & 0.997120(3) & 0.9987(2) \\
\midrule
& 2 & 0.97193(2) & 0.9830(7) \\
2 & 3 & 0.93118(5) & 0.9542(7) \\
& 4 & 0.92257(8) & 0.9486(7) \\
& 5 & 0.98844(1) & 0.9937(6) \\
\midrule
& 0 & 0.8450(1) & 0.905(2) \\
& 1 & 0.6931(3) & 0.726(2) \\
& 2 & 0.8618(1) & 0.8945(5) \\
& 3 & 0.90250(9) & 0.9233(9) \\
3 & 4 & 0.8487(1) & 0.8839(6) \\
& 5 & 0.9145(1) & 0.9382(7) \\
& 6 & 0.8884(2) & 0.9174(5) \\
& 7 & 0.9572(1) & 0.978(1) \\
& 8 & 0.97651(6) & 0.977(1) \\
\bottomrule
\end{tabular}
\caption{\footnotesize (9,16)}
\label{tab:table1_b}
\end{subtable}%
\\
\par\bigskip
\begin{subtable}{0.45\textwidth}
\centering
\begin{tabular}[t]{cccc}
\toprule
Band & L & $\mathcal{O}_{JK}^2$ & $\mathcal{O}_{EP}^2$ \\
\midrule
1 & 2.5 & 0.97230(3) & 0.9866(6) \\
\midrule
& 1.5 & 0.96685(6) & 0.980(3) \\
& 2.5 & 0.92390(9) & 0.956(4) \\
& 3.5 & 0.9075(3) & 0.9403(5) \\
2 & 4.5 & 0.9256(4) & 0.9541(4) \\
& 5.5 & 0.9920(3) & 0.9957(5) \\
& 6.5 & 0.97562(4) & 0.984(1) \\
& 7.5 & 0.9358(1) & 0.963(2) \\
\bottomrule
\end{tabular}
\caption{\footnotesize (9,13)}
\label{tab:table1_c}
\end{subtable}%
\begin{subtable}{0.45\textwidth}
\centering
\begin{tabular}[t]{cccc}
\toprule
Band & L & $\mathcal{O}_{JK}^2$ & $\mathcal{O}_{EP}^2$ \\
\midrule
& 1 & 0.97285(3) & 0.9834(9) \\
1 & 3 & 0.89744(10) & 0.9298(10) \\
& 5 & 0.97480(3) & 0.9863(6) \\
\midrule
& 1 & 0.8590(3) & 0.915(1) \\
& 2 & 0.8428(4) & 0.8925(8) \\
& 3 & 0.8859(5) & 0.9195(8) \\
2 & 4 & 0.8799(1) & 0.9139(10) \\
& 5 & 0.8939(3) & 0.9216(9) \\
& 6 & 0.9587(2) & 0.9752(9) \\
& 7 & 0.9286(1) & 0.9541(8) \\
& 8 & 0.94937(5) & 0.965(2) \\
\bottomrule
\end{tabular}
\caption{\footnotesize (10,16)}
\label{tab:table1_d}
\end{subtable}%
\caption{\footnotesize Main caption describing \subref{table1_a}, \subref{table1_b}, \subref{table1_c} and \subref{table1_d}.}
\label{tab:table1}
\end{table}
My main problem is that these are overlapping horizontally, although I thought \begin{subtable}{0.45\textwidth} would take care of this the way it does with \begin{subfigure}. I get the same problem using \subpar, and \subfloat seems to clash with some other of my packages.
Secondly I'd like their upper edges to line up, and thought the [t] in begin{tabular}[t]{cccc} would take care of this, but it doesn't.

\newcolumntype{d}[1]{D..{#1}}do? Is this aligning the numbers? And what does the multicolumn macro do? – jorgen Feb 18 '16 at 10:17dcolumnpackage provides a column type calledD. The\newcolumntype{d}[1]{D..{#1}}instruction creates a simplified interface, allowing me to writed{1.7}instead ofD{.}{.}{1.7}. The first.(dot) specifies the input decimal marker, the second.(dot) specifies the output decimal marker, and1.7says, "set aside space for one digit before the decimal marker and for seven digits after the decimal marker". Since all entries in a column of typedare expected to be numeric, the\mc{...}wrapper is needed to provide an override for the header cell contents. – Mico Feb 18 '16 at 10:25\begin{tabular}[t]{@{} l c *{3}{d{1.7}} @{}}, i.e. substituting the 2 for a 3. This aligns the numbers in the columns, but the last one has much more space than the first two. What's missing? – jorgen Feb 21 '16 at 09:56\mc{...}wrappers? Are two or moretabularenvironments being typeset side by side? – Mico Feb 21 '16 at 10:18