documentclass[a4paper]{article}
begin{document}
begin{tabular}{| c | c | c | c |}
hline
multicolumn{2}{|c|}{$a_{1}$} & multicolumn{2}{|c|}{$a_{2}$} \
hline
col1 & col2 & col3 & col4 \
hline
includegraphics[height=.2in]{./Figures2/paths/abc.jpg} & text & text & text\
hline
includegraphics[height=.2in]{./Figures2/paths/abc.jpg} & text & text & text\
hline
end{tabular}
end{document}