On this page of our game guide to Wasteland 3 you can find out what the toasters are for and why it's worth to repair them.
Toasters are some sort of a hallmark of the Wasteland series. They also appear in this installment of the franchise. You'll find them in many corners of Colorado (including the Ranger HQ). They contain many valuable items (for example, weapons and armor) that can strengthen your team.
Acquiring this equipment, however, is not that easy. In order to obtain and open them, you need the Toaster Repair skill.
The value of the items in relation to the skill points invested is quite moderate and rather moderately profitable. The exception here is a character that specializes in inflicting fire damage. Higher ranks of this skill have additional bonuses like Heating Element (7 ranks) and Toasty (10 ranks), which enhance that stat.