Tome of Knowledge is consumable item. The idea is simple. Let's say you play "carry". You need a comfortable environment to farm. someone can ward the map for you. Besides, he can go to their "nc" and annoy enemy heroes. This support hero need tome of knowledge. he deserved it. Carry can buy it for him or just let him buy for himself.(better buy it for him because he is not farming like you.)
I watched the replay of the game. Your teammate took and used the "tome of knowledge", but he apologized to you again and again. He bought two "tome of knowledge" for you and you consumed it. he tried to keep the game up while you are farming at jungle.
it is just an 150 gold item and it is a shareable item. you both shared it.
!Denied