What I usually take:
cereal and oats
long life milk
honey
couscous (easy to prepare!)
tins of beans, tuna, chick peas, sweetcorn
maybe a jar of pasta sauce or pesto
instant noodles or straight to wok noodles
cherry tomatoes, salad stuff, carrots, peppers, any veg that can be eaten raw or cooked
jars of olives
LOTS of snacks, dried fruit and nuts, crisps, biscuits, oat cakes, crackers, anything that the kids like that provides instant energy
bananas, apples, pears, tinned peaches
wraps, pita bread, rolls
cream cheese, cheese strings, laughing cow cheese, edam cheese
Basically, anything I know DS likes to eat that doesn't require much preparation and is easy to cook and keeps.
Sweets (especially good for handing out on long walks at regular intervals)
Healthy eating does go out the window a bit when I'm camping, but I figure DS needs the extra energy so I don't mind vast consumption of biscuits, crisps and sweets.
I would take some bought babyfood for the 7 month old, even if you don't usually use it, it might come in handy. Those healthy organic brands, there are a few on the market these days aren't there? Oatmeal and bananas also good.