All the names mentioned below are definitely of Sinhala, not Tamil origin. Therefore they would be Luso Sinhalese, not Luso Tamilians. If the author you are referring to called them as such, his credibility is in doubt.
Antonio Menezes wrote: One of the Luso - Tamilian descendent is one General Fonseka who as in charge of the Sri Lankan Army put a stop to civil war that ranged between Sri Lankans and Tamilians. Some Sri Lankan cricketers are possibly of Luso Tamilian descent like Aravinda de Silva, Charminda Vaas, Kushal Perera, Kushal Mendis, Agnelo Mathews etc. Roland. Toronto.