After Jabez asks for blessings so that he could be a blessing to others, he then adds:
“and enlarge my territory”
In Bible times, territory meant power via increased authority, responsibility, and influence.
As, such, a request for “more territory” is not a petition for more “stuff,” as much as a metaphor implying greater authority, responsibility, and influence. Again, this is for the purpose of benevolence, to help and aid others, not to be used selfishly or for personal gain.
Jabez wanted to have greater authority to assist those in need of an advocate, to be responsible to aid those who were less fortunate, and to positively influence his culture.
That is the good and proper use of power—and Jabez asked God to give it to him.