Charms of racecourse in Mauritius (7)
I believe the answer is:
mascots
'charms' is the definition.
('mascot' can be a synonym of 'charm')
'racecourse in mauritius' is the wordplay.
'racecourse' becomes 'ascot' (British racecourse).
'in' indicates putting letters inside.
'mauritius' becomes 'ms' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ascot' going inside 'ms' is 'MASCOTS'.
'of' is the link.
Can you help me to learn more?
(Other definitions for mascots that I've seen before include "Talismans" , "may bring fortune" .)