That sounds like a really bad idea. too much all at once.

I've seen many sites do that, but not side by side but one on top of the other. As long as you don't clutter above-the-fold with ads you'll be ok in Google's eyes.

Will it help CTR? I doubt it, in fact it could hurt CTR I think. Visitors to sites don't like to even look at ads and a big block like that screams 'ADS!'

Check out Google's 'heatmap' ad placement guide, they give good advice on how to place ads for high CTR.