{spreadtab} is a package designed for constructing tables in a spreadsheet-like manner. This tag should only be used for questions pertaining to the use of the {spreadtab} package.
spreadtab is a package designed for constructing tables in a spreadsheet-like manner. One of the functionalities of the spreadtab package is that it automatically assigns row and column indices to the entries in the table, and allows the user to use these indices to perform calculations in other table cells.
An example from the package documentation:
\begin{spreadtab}{{tabular}{rr|r}}
22 & 54 & a1+b1 \\
43 & 65 & a2+b2 \\
49 & 37 & a3+b3 \\
\hline
a1+a2+a3 & b1+b2+b3 & a4+b4
\end{spreadtab}