Probably not, ca made the ai so that all factions need to expand to survive. That's just the way the game is. If you care about historical accuracy you should try some of the mods. Also there is a thread about ai personalities but it seems that they don't mean much more than just determining what kinds of units and buildings the ai will build. This does have dramatic effects for certain factions but i'm not sure which is best for the ptolemies. In vanilla they're so overpowered anyways that their 'personality' really won't do much to slow down expansion.

Also, the vanilla egyptians are waaay overpowered (not to mention completely innaccurate in just about every other way) so if you want to balance them, maybe you can try to change their units' stats. A mod would probably be easier for you, though.