Magnetization is the default enchantment of all the Meteorite Tools and Armor. This enchantment's ability will attract dropped items toward you, similar to how experience orbs will slowly come towards you when you are near them. The effect does not cease when you have no room in your inventory because how would that actually make sense? You can't control Magnetization....or can you? There exists some advanced technology that will allow you to toggle the Magnetization ability, called the Magnetization Controller.

The enchantment has a max enchantment level of 4 (IV). With each level, it increases the range in which the dropped items will begin to attract to you.

range of effect = 8 blocks * enchantment_level

Meteorite Tools and Armor only come pre-enchanted with Magnetization 1 so you'll need to get the higher levels through other means, such as the Anvil or Enchantment Table.