First recall your favorite answer for:
What is TABLOCK for?
How let's look at something BOL says:
A table can be loaded concurrently by multiple clients
if the table has no indexes and TABLOCK is specified.
Let's see what MS Word's Thesaurus says:
concurrently -- at the same time as
Seems to conflect with the your favorite answer doesn't it.
Nevertheless BOL could be correct.
Anyone looking for an experimental challenge
could try experimentally observing
the correctness/incorrectness of BOL's statement.