Table formats - not setting properly

[Theresa de Valence]

I'm trying to set a Table format where the first column has no ruling at 
all (really, they're just the labels for the other columns), but I don't 
seem to be able to make this happen. If I try and create custom ruling, 
then it remvoes ruling from all the other column/cells in the table.

Is there something I'm not understanding correctly?

v 8

Thanks,
Theresa