Trivial Benefits - Leaving party

If the company arrange for a leaving lunch or party for an employee and their team, would that fall under trivial benefit exemption? Cost under £50 per head. This is not a retirement, but an employee who resigned. Are leaving meals/parties/gifts considered a reward for work performance?

Hi
Information on trivial benefits is available at :
Tax on trivial benefits which sets out the conditions for this exemption to apply.  
More detailed guidance including examples is available in the HMRC Employer Income Manual at :
Particular benefits onwards.  
If having considered all available guidance you are still uncertain as what tax treatment to apply you may consider making a non statutory clearance application.  
Guidance can be found at :
Find out about the Non-Statutory Clearance Service.
Thankyou.