The displacement will be ZERO as it did not move from its initial position but distance covered will be equal to the peremeter, i.e.
2(1+3)m = 2(4)m = 8m
The dimension of the table = 1m by 3m. Assume the table a rectangular (or parallelogram rarely)
Therefore, the length of the perimeter of the table = 2(length+breadth)=2(1+3)=8meter
Therefore the distance travelled by the book by its travellin onc along the perimeter and coming back to the starting point = 8meter.
But the displacement of the book considering its directions is =3m along the length +1m along the width direction -3m along the length and -1m along the width = 0, as the book is is at the starting postion only after all its travel.