About 15 years ago, when I played cash games on a personal computer, I liked playing at 4 tables and watching videos in the middle of these tables ))
Later, I started playing SnGs HU from a laptop and played up to a maximum of 6 tables at the same time, and I already watched the video with a maximum of one open table, because when playing HU, you need a much higher concentration than when playing cash games at FR tables...
And now I play only from my mobile phone and I think the best option is to play on no more than 2 tables at the same time...