How to create certain approval sheet?

Here's a tabularx approach to distribute the empty space between the lines nicely (can be done with tabular as well, with more work however)

There are 5 tabular(x) columns, the the 1st, 3rd and 5th one are restricted to a certain length, in the next line two table columns are squeezed together with \multicolumn to provide enough space for the 'name' of the person.

Use the 2nd solution to change the parameters such as vertical spacing etc. more easily!

\documentclass[oneside]{article}

\usepackage{tabularx}
\usepackage{blindtext}
\begin{document}
\parindent=0em
\blindtext



\renewcommand{\arraystretch}{1.5}
\begin{tabularx}{\linewidth}{@{}p{2.5cm}@{}X@{}@{}p{2.5cm}@{}@{}X@{}p{2.5cm}@{}}
\multicolumn{1}{c}{\textbf{Name}}& &  \multicolumn{1}{c}{\textbf{Signature}} && \multicolumn{1}{c}{\textbf{Date}} \tabularnewline
&  &  &  & \tabularnewline
\cline{1-1} \cline{3-3} \cline{5-5}
\multicolumn{2}{@{}l@{}}{(\small Advisor)} \tabularnewline[1ex]
&  &  &  & \tabularnewline
\cline{1-1} \cline{3-3} \cline{5-5}
\multicolumn{2}{@{}l@{}}{(\small Co-Advisor)} \tabularnewline[1ex]
&  &  &  & \tabularnewline
\cline{1-1} \cline{3-3} \cline{5-5}
\multicolumn{2}{@{}l@{}}{(\small Program Chairman)} \tabularnewline[1ex]
&  &  &  & \tabularnewline
\cline{1-1} \cline{3-3} \cline{5-5}
\multicolumn{2}{@{}l@{}}{(\small External Examiner)} \tabularnewline[1ex]
&  &  &  & \tabularnewline
\cline{1-1} \cline{3-3} \cline{5-5}
\multicolumn{2}{@{}l@{}}{(\small Internal Examiner)} \tabularnewline[1ex]


\end{tabularx}

\end{document}

A better variant (Easier to configure)

\documentclass[oneside]{article}

\usepackage{tabularx}
\usepackage{blindtext}
\usepackage{setspace}
\usepackage[letterpaper,margin=3cm]{geometry}
\newlength{\rulelength}
\setlength{\rulelength}{2.5cm}
\newlength{\extraverticalspace}
\setlength{\extraverticalspace}{1ex}


\newcommand{\personline}[1]{%
  &  &  &  & \tabularnewline
  \cline{1-1} \cline{3-3} \cline{5-5} % The lines
  \multicolumn{2}{@{}l@{}}{(\textbf{#1})} \tabularnewline[\extraverticalspace]% The name entry
}


\begin{document}
\parindent=0em

\begin{center}
\doublespacing
APPROVAL SHEET

BLA BLA
\end{center}

\blindtext
\bigskip

{\small\textbf{Signed by the examination committee}}

\renewcommand{\arraystretch}{1.5}
\renewcommand{\arrayrulewidth}{1.0pt}
\begin{tabularx}{\linewidth}{@{}p{\rulelength}Xp{\rulelength}Xp{\rulelength}@{}}
  \multicolumn{1}{c}{\textbf{Name}}& &  \multicolumn{1}{c}{\textbf{Signature}} && \multicolumn{1}{c}{\textbf{Date}} \tabularnewline
  \personline{Advisor}
  \personline{Co-Advisor}
  \personline{Program Chairman}
  \personline{External Examiner}
  \personline{Internal Examiner}
\end{tabularx}

\end{document}

Alternative (only a part).

\documentclass{article}
\newcommand{\signaturerule}{\rule{10em}{.4pt}}
\begin{document}
\renewcommand{\arraystretch}{1.5}
\begin{tabular}{ll}
    \bfseries Name  & \bfseries Signature \\
    \signaturerule &\signaturerule \\
    (Advisor)\\
    \signaturerule &\signaturerule \\
    (Co-Advisor)\\
\end{tabular}
\end{document}