Is it possible to eat too much salad? I don't intend to eat kg's of the stuff, but if I were to eat 3-4 handfulls of it, would it do harm?

Various leafs, carrot shavings, peppers, can of tuna, cucumber. With Pasta as a carbs source + olive oil for fats.

I'm a bit lost to work out the macro's for this type of thing.

What's the concern? Salad is one of the healthiest thing you could feed your body.

Check the macros out on fitday. You have to eat a LOT of salad to really build up the calories. That's one of the reasons it's so well known as a "diet food".

Eating too much maybe?

I guess I can enjoy my salads worry free.

Thanks Guava :D