Grid refers to the 10 equipped weapons for a given team.
% usually refers to assault/character atk.
Assault (small) has a base amount of 0%, (medium) gives 3%, and (large) gives 6%. Pride itself has a base amount of 0%. SR weapons with just assault are medium. SSR weapons with just assault are large. SSR weapons with two skills will have one being medium and the other being small.
Each skill lvl on a weapon with Assault or Pride adds 0.5% (regardless of small/medium/large).