This is the 3rd most frequent Tamil word.
என
"என" means "as," "like," "that," or "me/my" depending on context.
Here, 'எனக்கு' derives from 'என' and functions as a dative case marker indicating the action is for 'me'.
இந்தப் புத்தகம் எனக்கு மிகவும் பிடித்தமானது.
This book is very dear to me.
'என' functions as a conjunction meaning 'as' or 'in the manner of'.
தமிழ் பல்கலைக் கழகம் என அழைக்கப்படுகிறது.
It is called Tamil University.
Here 'என' means 'like' or 'as' in the sense of comparison.