∴ The main current is equal to the sum of each branch current,

∴IL=I2-I 1，

According to the data in the table, the current through the bulb is constant, 0.2A,

∫P = UI

∴ The electric power of the bulb remains unchanged,

∫P total = P heat+PL，

∴PL=P total phosphorus heat,

According to the data in the table, the electric power of the bulb is always PL=0.6W,

Therefore, the relationship between the total electric power P consumed by the circuit and the power P consumed by the sliding rheostat R is pTotal = pThermal+0.6W 。

So the answer is: P total =P heat+0.6W. 。