That God showed more favour to Israel (the people descended from Jacob), than to Edom (the people descended from Esau).
I think that "hate" and "love" are being used in an unqualified sense, *as though* God had unqualified loathing for Esau, not because God has any such attitude to Esau; but because the love of God for Israel, His chosen, covenanted people, is total, unqualified, and unreserved - just as the Israelite's love for God is called upon to be.
So, that, *by comparison* with God's covenant-love for Israel, God's love for other nations is as nothing. So, by a bold use of language, that love for Esau/Edom, the "brother" of Jacob not in a covenant-relation with God, is called hate.
God hates - in the familiar sense of the word - nothing that He has made. So the passage in St Paul, quoted from Malachi, is antecedently unlikely to mean that God hates Esau/Edom.