This is the 12338th most frequent Spanish word.
liviano
Light (not heavy).
The word 'liviano' is used to describe the physical weight of the bag, indicating it is not heavy.
Este bolso es muy liviano y fácil de llevar.
This bag is very light and easy to carry.
Here 'liviana' metaphorically describes the workload of the homework, meaning it is not overwhelming or demanding.
La tarea de hoy es bastante liviana, no te tomará mucho tiempo.
Today's homework is quite light; it won't take much time.
In this case, 'livianas' refers to the digestive quality of the meals, implying they are easy to digest or not heavy on the stomach.