It could be that the two bottles of relish were part of a treasure hunt. The clues led to these two bottles, and inside them were the next set of instructions or a small key.
I haven't heard of the 'two bottles of relish' full story before. However, it might be a story that involves a pantry or a kitchen setting. Perhaps two bottles of relish were the key ingredients in a special recipe, or there could have been a mix - up with the two bottles that led to some comical or unexpected events.
The bottles in the game are significant as they add an element of interactivity to the story. They can be used to cause distractions during combat, which can change the course of battles and thus affect the story.
In Bulletstorm Full Clip Edition, bottles can be used as part of the environmental interactions that add to the overall chaos and fun of the story. For example, they can be thrown at enemies as a distraction or even used in creative kill combinations, which in turn can influence the flow and enjoyment of the story experience.
A good way is to keep them in a special box or cabinet. Label each bottle with a brief note about the story it contains. You might also consider taking pictures of the bottles and writing out the full stories in a journal, so there's a backup in case the bottles are damaged.
They become full of stories through the events they are part of. For example, if a bottle is broken during a celebration, that moment becomes its story.
Well, without having read the '2 jars of relish short story', it might be that the jars of relish are central to the plot. Maybe they are used in a cooking competition in the story and there are all sorts of dramas and rivalries surrounding who can use them best. Or they could be a family heirloom that gets passed down and the story is about the generations who have owned them.