I am guessing here that the inverter is for the feed motor as it's too small for the main motor. If I'm correct, this will give you a variable speed feed in place of the original two speed feed - very nice. Presumably, it will be 240V 1ph in and 240V 3ph out. Check the nameplate on both the inverter and the feed motor to confirm this.
That leaves the main motor which drives the knife block round - much larger. If dual voltage, it MAY have been configured to a delta (∆) configuration to run on 240V 3ph, in which case you'll need another - larger- inverter to supply it with 3ph. Or it may be only a star (Y) wound motor which requires a more sophisticated type of inverter or a new motor.
More info needed!
Bob Minchin on this forum is your man - he's the resident guru.
Duncan