German德國
Table tennis 乒乓球
trainer 教練
just 只是
taught from book 從(from)書本(book)教學(taught) - word order in Chinese is different from English
If you tell him that 德國乒乓球教練只是從書本教學, he probably understands what you mean. I guess your another hidden meaning is the german trainer seldom shares his/her practical experience in table tennis skill or uses active, hands-on teaching and learning activities.