Multitabling should come natural, and its far more detrimental to play to many tables rather than to few. So by all means dont try to force this. But if you are feeling bored and find yourself watching Youtube or writing in CC forum while playing, then its probably a better idea to add another table or two to stay focused.
Also if you are playing for profit, then multitabling will allow you to increase your hourly winrate and overcome variance faster. So in that case its something, which you kind of need to learn. But you dont have to take it to extremes and play 24 tables at once, like some people did in the past.
Personally I play on a laptop, and after experimenting with different layouts, what work best for me is to have 4 tables running and have them tiled but partially overlapping, so that I can flip between the upper and lower on each side. In that way I dont miss out on to much action, and each table still has a size, where its easy for me to see, whats going on.
I sometimes have 5-6 tables running, but only for short periods of time. And I think, if you want to go boyond that, you need to be sitting at a desk with a 2 monitor setup. That will really make it feel like, you are "at the office", but if you are a very serious and maybe full time professional player, this is for sure the way to go.