Does eating before a blood test raise cholesterol levels?

Triglycerides. Yes, it can affect your total cholesterol. It's because eating prior to blood draw can increase the level of your triglycerides which in turn can affect the calculation of your total cholesterol, which uses a formula that includes triglycerides.
Only LDL Cholesterol. Eating increases triglyceride levels which affect the calculation of LDL cholesterol. Total cholesterol and HDL cholesterol are directly measured and are not affected by eating before the blood test.