area / space around images

Hi,
 
I am struggling to find anything to help me with this, partly because I am not sure of the language to be used.
 
It seems like a really basic question, but can you change the size of area the background 'dead' area of an image in photoshop? I'm talking about the space around the outside of images (in my case it's grey) which you can move around with the sliders. My issue is that it's super annoying to have this much space for the way I use photoshop. For example, if I need to select from one side of an image with the marquee tool to the other it will shoot my curser way outside the image and into this grey area, and I have to scroll back - really annoying!
 
I've attached a screen shot of an image, and how it looks to me in my photoshop. You can see there's an excess of grey 'nothing' area all around the image (this is just one side).
 
I hope this makes sense. I'm struggling to find the language as I said.
Please someone help, I've been tearing my hair out over this!
 
Thanks, 
Jane