documentclass{pnastwo}

usepackage{booktabs}
usepackage{multirow}
usepackage{siunitx} % makes the table screwed up...
usepackage[T1]{fontenc}
usepackage{amsmath}

begin{document}

title{Paper title}

author{Avi Ginsburg affil{1}{Somewhere over the rainbow}}

contributor{Submitted to Proceedings of the National Academy of Sciences
        of the United States of America}

significancetext{Quite insignificant.}

maketitle

begin{article}
    begin{abstract}
    {
        abstract (adjective) existing in thought or as an idea but not having a physical or concrete existence.
    }
    end{abstract}

    dropcap{H}ello world. Small is $SI{1}{angstrom}$ or so.

    begin{acknowledgments}
        We are grateful to egreg for expressing sympathy for those who have to use the PNAS class.
    end{acknowledgments}

    end{article}

    begin{table*}[ht]
        %   centering
        caption{Table title - We like to see them}
        begin{tabular}{c c c }
            toprule
            &
            textbf{Something} & textbf{Else} \
            & & \
            midrule
            multirow{6}{*}{rotatebox[origin=c]{90}{Random}}
            &   accidental &  \
            &   aimless & \
            &   arbitrary & \
            &   incidental & \
            cmidrule{2-3}
            &   indiscriminate & \
            &   irregular & \
            midrule
            multirow{5}{*}{rotatebox[origin=c]{90}{Example}}
            & case & \
            & illustration&\
            & lesson &\
            cmidrule{2-3}
            & object & \
            & part & \
            bottomrule
        end{tabular}
        label{tbl}
    end{table*}

end{document}