How to break a line in a table

Would a \parbox work?

\begin{tabular}{ll}
one line& \parbox[t]{5cm}{another\\column}\\
second line here& and here
\end{tabular}

\newline works in paragraph columns

Example:

\begin{tabular}{|p{3cm}|p{3cm}|}
first line
\newline second line & still on first line \\
\end{tabular}

Is this for a single cell, or an entire column of cells? If the later, try:

\documentclass{article}
\begin{document}
    \begin{tabular}{lp{.2\textwidth}l}
        42 & A paragraph of text & 42\\
        42 & Another paragraph & 42
    \end{tabular}
\end{document}

Even if it is for a single cell, I suspect that this is still the way to go.