It looks like you can multi-select (through ctrl-clicking or click-dragging), but it doesn't appear that that has any influence over the results. It seems to only choose one item from each row to search over.
It appears that there is some sort of spawning behavior near the darkened "Google" tiles. I paused, turned off all the cells in the region (taking into account wrapping from the other side) and let it go. Cells started activating near the 'e'.