Now I'm a growing man and I like my foods, I'm usually hunger throughout work but I bring in a good amount of food.
During my 7.5hr shift I eat;
2 pieces and ham w/ butter
1 packet of crisps (salt n vinegar or prawn cocktail)
1 apple
1 banana
1 hot roll / burger (microwave lunch)
1 chocolate bar
1 can of juice
2-5 cups of water.

And if any of my colleagues bring in chocolate boxes for the group I have some of them, today we have Cadbury Milk Tray and I've had a fudge and caramel from it.
So yeah... am I eating enough during my time at work?

Depends partially on portion size, partially on how active you are, and partially on other stuff. One option you have is to figure out roughly what sort of total energy intake you should be getting (there are magical calculators out there which may or may not be trustworthy), roughly how much energy is in the stuff you're eating at work, and work from there.

On a sidenote: your list seems unhealthy, though that may just be my reading of it.

also depends on what kind of work you do. Do you do hard manual labor?(Ie: lifting/moving heavy objects, swinging a hammer or something all day long?). If so, that is probably just barely enough food to keep you going in a day. I know when I used to lift 50-100lb boxes all day when I was younger(10 hour work shifts), I had 3 sandwiches, bag of chips, apple and banana, thing of yogurt, snack cake, and I'd usually end up grabbing something from the snack machine. Never gained an ounce while doing that either, I burned all my calories off and then some. Any less food then that and my day would be horrible, I'd be tired and not able to lift the boxes nearly as quick.

No I sit at a desk and am effectively paid to look pretty
Now and then I go a walk around the building for a 5-10 minutes, besides that I'm sitting infront of a screen or read my book.

Hmm, I would say then, that unless you get a significant amount of exercise outside of work, that you may be eating just a little bit to much, considering you're not doing much at all while working.

Not much exercise besides jogging when out with the dog.
I think I need more, always left feeling hungry after eating the most of it, it's all disrupted throughout the day, from 10 everything's eaten 1 after the other. Maybe it's a case of I'm eating out of boredom.
On a healthy note I'm actually getting healthier than previous years where I've ate less.