This is the 758th most frequent Afrikaans word.
daai
"Daai" means "that" in English.
In this sentence, 'daai' is used as a demonstrative adjective to specify or point out 'boek' (the book).
Ek hou van daai boek wat jy lees.
I like that book you are reading.
Here, 'daai' functions as a demonstrative adjective to refer to 'fliek' (the movie) of which the speaker assumes the listener is aware.
Het jy daai fliek al gesien?
Have you already seen that movie?
'Daai' is used in this context as a demonstrative pronoun referring to 'instruksies' (the instructions), indicating specific instructions previously mentioned or known to both speaker and listener.