Hydrogen is not in the first group as it was before and it is now placed above the periodic table? So why is it still categorized as a metal in some books?
There is a lot that could be said about this question, but a simple explanation goes like this:
Some periodic tables categorize hydrogen as a metal (or at least an alkali metal) because it has one electron in its outermost orbital - just like Lithium, Sodium, Potassium, etc., which are obviously metals.
Other authors of chemistry textbooks realize that hydrogen seems to love the gas-phase so much over the solid phase that it just doesn't make sense to call it a metal, irrespective of what atomic orbital pattern may tell us.
Hence the differences between authors of texts and where they put Hydrogen on their periodic table.