Hey Dimitri, ok so I would definitely agree that having very big arms and shoulders is not ideal for table tennis as you tend to be a bit less mobile and agile compared to someone with a more slight build. But like most things in life there is a balance if you maintain good all round cardio fitness and flexibility then I’m sure you can still make good improvements in table tennis. So I wouldn’t reccomend going over board on building the arm muscles and bigger shoulders if you want to really improve at table tennis. The most important things I would say are flexibility, agility , speed, the lower body, core strength and balance These are the key elements that make up the top level players and even if you don’t want to be pro they will all still really help you make improvements.
I’m sure right now it won’t hold back your development but it’s something to be aware of in the future and just getting the balance right between gym work and table tennis playing time. I hope this helps and if you need more info or have other questions on this topic, just get back to me on here.
Thanks, Tom