\begin{table}%t1
%\centering
\par
  \caption{Ratio between the mass in the finger and the mass in the shell at $T=5~ t_0$
and $T=10~ t_0$.\label{tab:tab1}}
  $$
\begin{array}{p{0.3\linewidth}p{0.3\linewidth}p{0.3\linewidth}p{0.3\linewidth}p{0.3\linewidth}p{0.3\linewidth}l}
 \hline \hline
   $T= 5~ t_0$& \\
    \hline
    \noalign{\smallskip}
    $\sigma$   &  $\pi/6$  &  $\pi/8$  &  $\pi/12$  &  $\pi/16$  &  $\pi/24$  &  \pi/32 \\
    \noalign{\smallskip}
    \hline
    \noalign{\smallskip}
    0.0    & 0.10 & 0.25 & 0.60 & 0.70 & 1.30 & 2.00 \\
    0.0025 & 0.05 & 0.15 & 0.45 & 0.60 & 0.75 & 0.75 \\
    0.005  & --  & 0.10 & --  & 0.50 & --  & 0.60 \\
    0.01   & --  & 0.05 & --  & 0.30 & --  & 0.35 \\
    0.03   & --  & 0.00 & --  & 0.00 & --  & $--$\\
    \hline
  \end{array}
  $$
  $$
\begin{array}{p{0.3\linewidth}p{0.3\linewidth}p{0.3\linewidth}p{0.3\linewidth}p{0.3\linewidth}p{0.3\linewidth}l}
    $T=10~ t_0$ & \\
    \hline
    \noalign{\smallskip}
    $\sigma$   &  $\pi/6$  &  $\pi/8$  &  $\pi/12$  &  $\pi/16$  &  $\pi/24$  &  \pi/32 \\
    \noalign{\smallskip}
    \hline
    \noalign{\smallskip}
    0.0    & 0.30 & 0.55 & 1.20 & 1.80 & 3.50 & 4.20 \\
    0.0025 & 0.25 & 0.40 & 0.70 & 0.75 & 0.80 & 0.75 \\
    0.005  & --  & 0.40 & --  & 0.75 & --  & 0.70 \\
    0.01   & --  & 0.20 & --  & 0.60 & --  & 0.35 \\
    0.03   & --  & 0.00 & --  & 0.00 & --  & $--$ \\
    \hline
  \end{array}
  $$
\end{table}