The library need 1591 bytes flash-memory and 2 bytes sram in textmode, in graphicmode library need 2823 bytes flash-memory and 1026 bytes static sram so you can use oled-displays e.g with Atmega48PA (only with textmode).
If you want to use characters like e.g. รค set your compiler input-charset to utf-8 and your compiler exec-charset to iso-8859-15 (look at makefile line 115).