We (Sport Europe) organize several training days/camps for table tennis players of all levels and all ages each year. These training days pay a lot of attention to table tennis such as tactics, technique, and service. But of course, there is also plenty of time for other relaxing activities.
There is also the possibility for your association to organize the training camps/days themselves and hire our professional trainers for this purpose. For example, we could give an extra boost to a season opening or closing.