[blackjackiisre]

Russians - maskoliai, ruskiai
Poles - pšekai
Belarussians - bulbašai
All those from south Asia and near east countries - babajai

And where is the term for Latvians- horse heads?

As for what I can remember about Latvian terms-
Jews- Žīdi (it's kind of perceived as despective, but is more like politically incorrect)
Russians- Vaņkas
Estonians- Kurrati