how to style tables

Hello,

I have few problems formatting tables with Atahualpa. I don't want to use Formidable Plugin because it is not user friendly for updates so I coded the tables in html.
First of all, I try to remove space between 2 boxes here. In ATA options>table style I wrote "border: none; border-collapse: collapse; float:top;" but it doesn't work.
Second issue, I would like to have the text beginning at the top of the box and not centered : I didn't manage to find the solution.
Anybody could help me? Thanks in advance.
isabelle