My mental image of playing a (3rd? 1st?) person shooter on a table is like, is horrible. How do the controls work? Do you just pair some controller and prop up your iPad on a surface in front of you? Or is the controller attachable like a Switch?
Why the table? Just place the tablet on your laps and use both hands (vigoriously ;).
There are many techniques - the advanced players use most of their fingers constantly. Touch controls could be very elaborate and precise.
It's not. I ended up putting thousands of hours into Fortnite on iOS too (so glad it got pulled - that stopped me playing!)
Playing on the table is one way - but it hurt my neck too much. I preferred the "claw grip" on my phone while laying on the couch - though I could only comfortably do 3 fingers. Some of the best mobile players do 6!