My son reaaally wants to help me with everything, including my work. I really try to encourage it, as I remember one of my siblings started out as a wannabe helper... and then when that didn't work out, became much more oppositional/defiant. So when he asks if he can help, I leap to my feet and create little tasks/missions he can do for me - he loves it!
I have to admit that it can be exhausting though.