\documentclass[a4paper,12pt]{article}
\usepackage{rotating}
\usepackage{tabularx}

\begin{document}
\pagestyle{empty}

\begin{sidewaystable}
  \begin{tabularx}{7cm}{|l|X|X|}
  \hline
  \textbf{normal} & \textbf{tilted} & \textbf{wider} \\
  \hline
  normal & \rotatebox{30}{I'm tilted!} & wider \\
  \hline
  \end{tabularx}
\end{sidewaystable}

\end{document}