\documentclass{article}
\begin{document}
\begin{center}
	{   \footnotesize{ Table 1: The plot (A) shows the approximate solution (4.8) when shows the  approximate solutions expressed  values of $ \alpha $ when $  t=0.6 $}}
	$$\begin{tabular}{|c|c|}
	\hline
  Exact &  Absolute error \\
	\hline
0.0     &    0.0              \\
	\hline
	\end{tabular}
	$$
\end{center}
\end{document}
