I used _tabularx _package. Additional definitions:
\usepackage{array}
\newcolumntype{L}{>{\raggedright\arraybackslash}X} % left multiline alignment
\newcolumntype{R}{>{\raggedleft\arraybackslash}X} % right multiline alignment
Table:
\begin{tabularx}{\textwidth}{@{}p{0.8\linewidth} R}
Text, aligned to the left, without margin \newline
Tex in the same cell on the next line
& % next column delimiter
Text aligned to the right \newline second line
\end{tabularx}
Here we have one columt with 80% width and one column with right alignment
@{}
is required to suppress left margin in the first column.
Results: