While Niels is correct that the difference between Team Lead and Principal QA roles is company-specific, there are some generalities:
Team Lead - will typically lead a team. The team lead of a QA/Testing group is likely to be the most experienced or most senior member of the group. Responsibilities are likely to include mentoring other team members, ...
This is very company specific. Roles and responsibilities is similar to testing terminilogy everyone means something different with the same words.
Think what type of work do you like todo? Manage people, or be more specialized. How much money do you want to make? Discuss this with HR instead, they can figure out which title you should persue.