\usepackage{colortbl}
\usepackage{arydshln}
\usepackage{multirow}
\usepackage{multicol}

\begin{table}[htbp]
\small
\renewcommand{\arraystretch}{1.3}
\centering
\begin{tabular}{|l|l|m{170pt}<{\centering}|}
   \hline   
    \textbf{Category} & \textbf{Types} & \textbf{Primary Argument} \\
   \hline
    \multirow{5}{2cm}{Simple Event} & Transcription & Theme(Protein) \\      
    \arrayrulecolor{gray} \cdashline{2-3}[0.8pt/2pt]
    & Gene$\_$expression & Theme(Protein) \\
    \cdashline{2-3}[0.8pt/2pt]
    & Protein$\_$catabolism & Theme(Protein) \\
    \cdashline{2-3}[0.8pt/2pt]
    & Phosphorylation & Theme(Protein) \\
    \cdashline{2-3}[0.8pt/2pt]
    & Localization & Theme(Protein) \\
    \hline
    Binding Event & Binding & Theme(Protein)+ \\
    \hline
     \multirow{3}{2cm}{Complex Event} & Regulation & \tabincell{c}{Theme(Protein/Event), Cause(Protein/Event)}\\    
    \cdashline{2-3}[0.8pt/2pt]
    & Positive$\_$regulation & \tabincell{c}{Theme(Protein/Event), Cause(Protein/Event)}\\
    \cdashline{2-3}[0.8pt/2pt]
    & Negative$\_$regulation & \tabincell{c}{Theme(Protein/Event), Cause(Protein/Event)}\\  
   \hline
\end{tabular}
\caption{Event types and primary arguments}
\label{event:eventTypes}
\end{table}

效果如下：