No i dont believe the Bible allows slavery, although it does show a history of slavery.
And i dont believe God created slavery, it sounds like Noah cursed his son and thats how it came about.
24 When Noah awoke from his wine and knew what his youngest son had done to him, 25 he said,
“Cursed be Canaan;
a servant of servants shall he be to his brothers.”
Lamech ended up taking at least two wives, and i wouldnt say God created polygamy. The people just started doing it. And God also outlawed polygamy part way through the Bible.