Set EEPROM from PC before program
The simplest way would be to have two sketches. 

One that will store all the strings into EEPROM. 

After that you can upload the second actual sketch that uses the values stored in EEPROM. 

You only need to upload the first sketch if any of the strings change.

There is a way to upload a hex directly to the EEPROM using avrdude, but you'd have to use the commandline, and also have some way of generating this hex file containing all these strings.