I tried several different sizes before I settled on the ones I have today. The 4 by 8 ft. was great except I was always trying to reach for tools etc. When I moved the garage was empty and the first thing I did was outfit it with benches and cupboard space down the three walls. I purchased 6 solid core doors that had slight damage for around 25 bucks each. They were perfectly straight and putting the damaged side down made for perfect bench tops. I ended up only using 4 for the bench tops and instead of benches I ran full length cupboards down one side and across part of the end of the garage. That left two that I turned into building tables. The full length door is on a 2 by 2 inch steel tube frame I built with casters and leveling jack screws and the second is shorter 5 ft. long on a bench that houses the 36 inch wide zerox machine below. The top swivels up and the front down to access the zerox machine. Both are covered with Homosote and have remained warp free for over 20 yrs. as have the bench tops. When working on big projects I can add ends to lengthen the building surface and move it to the middle of my work space so I can work all around as needed. The 32 inch width is plenty big enough and I can easily reach across from either side.
Dennis