Forming Norton generator from a voltage source and two resistors
Can I combine the E,R and Xl to form a current generator,


Yes. Any 1-port linear network, other than an ideal voltage source, can be modeled by a Norton equivalent circuit.


  ... with R and Xl in parallel.


No. 

To find the Norton equivalent circuit, you need to find two points along the one-port networks' I-V curve, and then determine the equivalent current source and shunt admittance from that. Typically it's easiest to use the short-circuit output current and open-circuit output voltage as the two points.