Keeping hands in pockets or under a table suggests the person is hiding something or feels defensive.
Based on the renowned History Channel documentary The Secrets of Body Language los secretos del lenguaje corporal canal historia parte 1
Part 1 uses real-world examples to show how body language can contradict spoken words: Keeping hands in pockets or under a table
Body language isn't a universal "one size fits all" dictionary. The documentary notes that cultural differences los secretos del lenguaje corporal canal historia parte 1