Uprading The enchantment table

You should be able to upgrade your enchant table. This would cost certain amounts of xp and lapis, depending on how many times you have already upgraded it. 

Level 1 

5 levels and 3 lapis

Level 2

10 levels and 5 lapis

Level 3

15 levels and 10 lapis

Level 4

20 levels and 15 lapis

Level 5 (Max Level)

25 levels and 25 lapis

Upgrading your enchantment table could 1 of 3 things.

1 increase the chance for rarer enchantments, like mending, or Looting.

2 decrease the amount of lapis or xp it takes to enchant an item

3 increase the chance for multiple enchants on one item.