Your laptop is not magical. It cannot create power out of nothing. That power brick converts the AC power at your wall into DC power. This is usually 20V DC power, that then gets converted again to the various voltages your laptop needs.
Volts x amps = watts. 20V x 4.5A = 90W. The draw at the wall will be more, because the brick is not so efficient. So It might need 1.4A of 115V power... and the difference is lost to heat. You notice how hot your brick gets while the laptop is charging, I'm sure.
Those wattage numbers you gave are not even the maximum draw of those items... it's what they are rated for thermally.http://en.wikipedia.org/wiki/Thermal_design_power
However, none of that actually happens continuously. While your power supply is steadily supplying maximum power until the battery is charged, the computer is using varying amounts of power. So, it can draw more than it's getting because it has a reserve.
If you do try to use more power than you have available, the laptop has ways to limit itself. It won't run at full speed if it doesn't have the available power.