\begin{tikzpicture}
  \begin{axis}[
    title=Import from table,
    xlabel={$x$},
    ylabel={$y$},
    legend pos = outer north east,
  ]
    \addplot [blue] table
    {codebeispiele/pgfplots-data.dat};
    \legend{$\approx x^2$}
  \end{axis}
\end{tikzpicture}