\begin{tabular*}{\textwidth}{@{}lp{\descrwidth}@{\extracolsep\fill}rlrr@{}}
\textbf{Number} & \textbf{Description} & \textbf{Qt'y} &
\textbf{Unit} & \textbf{Price} & \textbf{Amount} \\
\begin{tabular*}{\textwidth}{@{}lp{\descrwidth}@{\extracolsep\fill}rlrr@{}}
\textbf{Number} & \textbf{Description} & \textbf{Qt'y} &
\textbf{Unit} & \textbf{Price} & \textbf{Amount} \\