What are "Yegevim"?
Rashi: They are fields to cultivate. Yegivah is an expression of digging in the ground. (In Melachim II, 25:12, Rashi said that this is like Yekevim 1 , i.e. pits in the ground (to press wine).)
Rashi (52:16, from Shabbos 26a): They are people who hunt the Chilazon 2 [Radak Melachim II, 25:12 - from the ladders (steep inclines) of Tzur until Chaifa].
Ramban (Shemos 28:31): The letters Gimel and Kuf are sometimes interchanged (because they are articulated from the same place in the mouth - Harei Besamim 2 155).
Why did he leave the poor people, and not exile them?
Malbim: He knew that they would not rebel against him, for he gave to them vineyards and fields.