Once the little plants get a bit bigger, you can separate them, using a scalpel to cut them apart.
They don't mind being crowded together, but eventually, the strongest ones will overshadow the weaker ones, and they'll die, or at least struggle.
To get the most bang for your buck, you want to start to pull them apart early. You can use tooth picks to gently separate them, giving them more room while leaving them attached to the mother leaf for as long as possible.
Put a tooth pick into the soil below the tiny plant, and stretch the plants out so they can get more light.
Do this for a week or so, moving the tooth picks every day or so, until they show that they are self sufficient.
After a few weeks of this you may be able to cut the biggest ones off and pot them up individually.
Give them lots of light - a grow light is best. More on grow lights here.