The main difference is the physical state of the active substances. In the drops, the hawthorn, motherwort and valerian extracts are already in solution, whereas a tablet or capsule first has to dissolve in the stomach. For some people this means a more predictable onset of action, although individual response always varies.
The second practical point is flexible dosing. Drops let you measure out the amount you need drop by drop, which is convenient if you need to adapt intake to a particular routine or introduce the product into your diet gradually. A tablet does not offer this option.
The solvent also needs to be taken into account: liquid herbal drops usually contain alcohol as an extractant and preservative. This is worth bearing in mind for anyone who avoids alcohol for medical, religious or personal reasons. It is recommended to read the ingredients on the pack before use.
Finally, taste and aroma are not a minor detail. The mint and lavender in the formula make taking the drops a more pleasant ritual, especially in the evening, when you want to switch off after a busy day. For those who find tablets hard to swallow, the liquid form may simply be more convenient.