There are four forces acting on the heavy table. They are normal force (upwards), gravitational force (downwards), push and friction (opposite to push).
Let’s take
Normal force = N (- ve); Gravitational
Force = W (downwards); Push = F1
Friction = F2 (- ve) [more]
∴ Net force in X – direction = Push – Friction = F1 – F2 = – ve
Net force in Y – direction = N – W = – ve
As the net force in Y – axis is more you are unable to move the heavy object.