Full recovery model and tablock inserts logging
When using TABLOCK your logging even in full model is called "efficient logging", it's when instead of logging every insert row-by-row the whole pages are logged.

It would be minimally logged in simple and bulk logged modes with only page allocations in the log, but in full recovery model you have fully formatted pages of data.

So the number of records that go to the log in simple and full models when inserting with tablock will be nearly the same but the content is different: in simple/bulk logged there will be only page numbers, in full there will be complete pages.

And it is really full logging since the insert operation can be fully reconstituted using these log records while in simple/bulk logged you have only information sufficient to rollback the insert.