Item | Cost
-------------- | -------------
Rent | $1500
Utilities | $200
Groceries | $360
Transportation | $450
Entertainment | $120
**Total** | `=SUM(B2:B6)`
https://github.github.com/gfm/#tables-extension-Getting rid of the vertical divider is nice but I'd rather think of it as a tiny modification to GFM than a distinct language.
Putting the in backquotes could make it look more like a formula and also it could be required for formulas to prevent accidentally invoking it.
It really is nice to have the horizontal bar gone, though. I think I might make my own format based on it. I tried to get rid of the bar but saw that you can't. In fact the only way you can have everything on one side of the bar is to only have a header (thead) when it would often be useful to only have a body (tbody).
FWIW original markdown requires pipes at the start and end of each row but not GFM.