% Alignment outside a table should not affect alignment inside tanle
\def\tbl{%
\begin{calstable}
\colwidths{{100pt}}
\def\cals@paddingT{10pt}
\def\cals@paddingR{10pt}
\def\cals@paddingB{10pt}
\def\cals@paddingL{10pt}
\brow
\cell{\noindent\vbox to 20pt{}}
\ht\cals@current@row=40pt
\showbox\cals@current@row
\erow
\end{calstable}
}

\tbl

\begin{center}
\tbl
\end{center}

\begin{flushright}
\tbl
\end{flushright}