I am not a native English speaker. When I see medicines with label stating "Take this with a meal" what does it actually mean?
Before starting the meal
After finishing the meal
Any of the above.
That is what it actually means. Take it while eating a meal, or after you have already started eating the meal. The idea is not to take it on an empty stomach. (Note this is not medical advice and you should consult your doctor if you have questions about the prescription or nonprescription medicine.)
Some medicines may upset an empty stomach. Some medicines may work too quickly if taken on an empty stomach. For the same reason, doctors may prescribe some medicines to be taken on an empty stomach.
Some medicines interfere with the work of other medicines, and so they shouldn't be taken within two hours of each other.