I believe that is in reference to the Size Table on p. 179 of the core rules. Large (Size 4-7) add +1 to Wounds, Huge (8-11) gain +2 Wounds, and Gargantuan (12-20) gain +3 Wounds. I don't otherwise understand the "max wounds of 2" thing? Size on p. 178 only states "Additional Wounds: Large creatures can take an additional Wound, Huge can take two, and Gargantuan three. The maximum Wound penalty is always three. This stacks with Resilient/Very Resilient (see above). Such creatures typically have Reach equal to the additional Wounds granted by Size." There is Resilient/Extra Resilient, but that just makes where a non-Wild Card NPC would actually have Wounds (+1 or +2). Normally a non-Wild Card would have none (just Incap., so they're up or they're down). Of course all of that are for NPCs in the the Bestiary section and those are just guidelines for creation as the overarching rule there is for a GM to just make them how they want them ("They are not created like player characters (though they should generally have the prerequisites of any Edges for completeness)", emphasis in the original).
For PCs the Size table wouldn't necessarily apply, especially since p. 11 explicitly states "Size: A hero’s default Size is 0 unless altered by racial abilities, Edges, or Hindrances. It cannot be less than −1 or more than +3." So a PC should never end up into that Large size category anyway, at least not by RAW. Although the Negative Racial table does reference that table on p. 179, but only for size reduction, not for larger version. p. 106 also references it but, again, I think it's overwritten by the main rule for PCs that limit them to +3 Size, FWIW.