在...的帮助下adjustbox
:
\documentclass{article}
\usepackage{adjustbox}
\usepackage{hyperref}
\begin{document}
\begin{tabular}{p{29em}r}
\adjustbox{valign=t}{\TextField[name=W,multiline=true,width=\linewidth,height=3\baselineskip]{}} %
&(2)\\
\end{tabular}
\end{document}