TLC is most often understood as a TLA for Tender Loving Care. It arose sometime in the mid-1900s in the field of nursing; a good nurse should be tender and compassionate when caring for their patients. It expresses the idea that sometimes all that is needed to make someone better is for someone to take care of them in a sensitive fashion, rather than operate, medicate, and perform tests on them.

Newbies just need some TLC while they adjust to the culture of E2.

These days there are a lot of businesses in the health, educational, and non-profit fields that carefully pick a name so that they will be able to acronym themselves as TLC in order to bring to mind feelings of tenderness and compassion; Talk, Listen, Connect, The Love of Christ Ministries, Teens Living For Christ, Teaching, Learning, and Computing, Teach, Learn, and Communicate, Inc., Transgender Law Center, etc. etc. There are many too many to be worth noding (or even listing) all of them.

Of course, there are many things that TLC stands for that you may have come to this node in order to learn about; here are some other meanings:
The Learning Channel
Total Lung Capacity
The Learning Company
Toyota Land Cruiser
Tastes Like Chicken
Trilateral Commission
Tables, Ladders, and Chairs Match