Very Large Table Partitioning

Hi guys.

here is our problem:

We have a table that if we want to save all user's records in it, we
have a very large table. maybe 10TB+
so we are deciding to use table partitioning. But again we have problem
here:

if we decide to partition table per user we have lots of tables (maybe
more than 100000+) with only 10000 records each.
is this a good idea? is there any limit for number of tables?

The table structure is not in a way that we can partition in a better
way. is this a good idea to add a column like "date inserted" and
partition per year for example?