Custom tables dont support translation. your best bet is to add a new column to your table to indicate which culture that row relates to.
I.e.
FruitId | FruitName
---------+------------
1 | Apple
2 | Banana
3 | Cherry
becomes
FruitId | FruitName | Culture
---------+------------+--------
1 | Apple | en-GB
2 | Banana | en-GB
3 | Cherry | en-GB
4 | Jabłko | pl-PL
5 | Banan | pl-PL
6 | Wiśnia | pl-PL
You can then filter your queries based upon culture.