enchantment table seems off, not working properly

7" RCA Android Tablet - I'm at lvl 30 and have 15 bookcases surrounding enchantment table, however the enchantments do not seem proper. For instance a bow at lvl =<30 will only provide Punch 1, and a Sword at lvl =<30 will only provide Smite 3... from what I remember I should be able to get Infinity and Flame 4