Wasn’t aware I could do that but so useful to know. Thank you.
That is the whole point of a basal/bolus regime (lantus is your basal, novorapid your bolus).
In an ideal world (which we know doesn't exist) your basal would cover all your insulin needs if you ate nothing at all. You'd then inject bolus to match your food intake whenever you ate (whether that's one meal a day or 6 snacks). This gives you the flexibility to match your insulin to your food rather than your food to your insulin.
Ideally, your clinic would give you some numbers
1) your basal/lantus amount - if this is right you should stay level overnight.
2) insulin to carbs ratio eg 1 unit of insulin to 10g of carbs. This can vary widely from person to person and even by time of day. So if that was your ratio and you had a 30g of carb easter egg snack you could inject 3 units of insulin before it.
3) correction ratio - if your blood sugar is too high before a meal you can add in some extra bolus (novorapid) to the insulin for your carbs, so as to bring it down eg 1 unit might bring you down by 3 mmol/L. This figure also varies widely from person to person.
But there are lots of reasons why the above rules don't always give you the results you want - illness, exercise, stress etc etc all affect your insulin needs and sometimes all you can do is keep testing and injecting. (And don't forget that if you do a blood test before your novorapid has run out you should be careful to allow for the insulin in your system when you inject more as a correction - it may go down fine on its own.)
Good luck, and I hope you enjoyed your egg.