The tablet is designed to dissolve in the mouth, not to be swallowed whole. This is the main point of the lozenge format: it can be taken without water and fits into a day where you may be at a desk, in a class or travelling. Place a tablet in the mouth and let it dissolve slowly rather than chewing it like a regular tablet. Because it dissolves, it is also a practical option for people who dislike swallowing standard tablets.
For exact frequency and timing, follow the package instructions for this specific product. General advice for food supplements is to use them consistently as part of a daily routine, but not to exceed the amount stated on the label. The product is intended for times when the nervous system and concentration are under extra strain, so it can reasonably be used on busy workdays, study sessions or other mentally demanding situations, but the leaflet remains the reference for how many tablets to take.
If the product is intended for a child, it is sensible to consult a doctor or pharmacist first. Keep the tablets in the original packaging, in a dry place and out of reach of small children, as with any supplement.