In emacs-calc, the simple product of 2 vectors calculates the dot product.
This works (I put the result in @6$3
; also the parenthesis can be omitted):
| a | b | c |
|---+---+----|
| 3 | 4 | |
| 1 | 2 | |
| 1 | 3 | |
| 2 | 2 | |
|---+---+----|
| | | 21 |
#+TBLFM: @6$3=(@I$1..@II$1)*(@I$2..@II$2)
@I
and @II
span from the 1st hline to the second.