Can I charge more than one enemy unit?

With a single movement? No

Page 52 of the RRG: A unit cannot move in such a way that its minis would be placed in base contact with multiple enemy units.
»» It is possible for a unit to be in a melee with multiple enemy units if another unit joins later.

Whether or not you have the Charge keyword, you can not get into base contact with more than one unit with a single move.