Quick question about populating arrays

If you swap two lines around in the struct you could just do:
sliderButton_t button[10] = { {50}, {84}, ... and so on.

  byte xEEPROM;         // EEPROM adresss for stored value
  int  xPos;             // Stored value for X position

Becomes:

  int  xPos;             // Stored value for X position
  byte xEEPROM;         // EEPROM adresss for stored value

Unless you are relying on the position of each item in the struct then the above would work fine.