Tons of ready to eat stuff is available
As well as Sausage rolls:
Cold ready to eat items:
Pork pies, quiche, other pies, samosas, cocktail sausages, scotch eggs, salads (these often come with a fork or even if you're not buying a salad there's often disposable cutlery to grab in the sandwiches/salad section), pasties, cooked tarts, cooked diced chicken, Spanish tortilla, falafel, ham slices etc (just roll up and eat), anti pasti/sides - olives, sundried tomatoes, stuffed peppers, stuffed vine leaves, bread sticks, carrot sticks, celery sticks (can be dipped in the houmous) artichokes, snacking cheese items, fridge raiders also sandwich fillers like egg Mayo
Can be made hot with just a kettle :
Pot noodle
Pot pasta
Cous cous
Noodles
Check out the chilled veggie section even if you're not veggie as there's loads there