Ballroom Etiquette - Improper Amorism is the /dote emote tome.
The error you got when attempting to use (right click) that tome is due to you already learning /dote.
To see if you actually have that emote, type /dote in your chat.
If your character blows a "heart" kiss, then you already have that emote... if you do not have that emote, then your character will do nothing.
You can also access your emote window, via Social/Emotes in game, click the magnifying glass icon and type /dote.... if it is already in your list, it will show the emote and it's icon.
If you already have learned the emote, and have bought a second copy of that tome, you can put in a "return / refund" request via the Support ticket system.