\documentclass{minimal}
\begin{document}

\begin{tabular}{cc}
    \begin{tabular}{c}
        Cell 1
    \end{tabular} &
    \begin{tabular}{c}
        Cell 2
    \end{tabular}
\end{tabular}

\begin{equation}
    \begin{aligned}
        1 &
        & 2 \\
        3 &
        & 4 \\
    \end{aligned}
\end{equation}

\begin{environ*}
  A &= 10
    \\&= \command{
  something
}
\\&= 20
\end{environ*}

  \end{document}
