elevated LDL and history of heart disease

Had a blood test recently for the first time in many, many years and most of my numbers were fine apart from my cholesterol levels, which I'm not too surprised about given I have a family history (father who had a mild heart attack around 66 and has several stents but still going ok in his mid 80s). I'm in my early 40s, excercise at intensity 2-3 times a week, lean and fairly athletic, BMI 23, avoid red meat and don't drink or smoke.

BUT I do snack in small quantities but it's very regular and I think that's my issue - roughly per day - 2-3 biscuits, 2-3 squares of chocolate, crisps bag x4 times a week with lunch usually, occasionally a few other treats here and there. So I think that's why I need to cut down on but also with my family history, I'm worried that my LDL will always be fairly elevated. No symptoms during excercise or sport or any other symptoms. Here are my numbers -

Cholesterol 5.9 mmol/L
Triglycerides 1.29 mmol/L
HDL Cholesterol 1.55 mmol/L
LDL Cholesterol 4.28 mmol/L
Total cholesterol: HDL ratio 3.81
HDL % of total 26.27 %
Non-HDL Cholesterol 4.35 mmol/L

My LDL level is really elevated but the other numbers aren't too bad.