Question
will a mason jar make this difficult or impossible for some reason? Could I fill the jars with acrylic raindrops first and then slide lemon or lime slices down the sides? If not what do you recommend as the likeliest material to insert to hold the slices against the interior sides that also won't interfere with the ability to insert a flower arrangement? Because I will have limited refrigerator space for 14 table arrangements, I am thinking to cool just the fruit sliced lined mason jars and then arrange the flowers the day of the wedding. Does that sound like a good idea? Will fruit cloud the water?

Answer
I don't know which size jars you are using, as they come in many sizes.  The sliced fruit would be easiest to insert into the lowest size with the widest mouth.  I usually bunch up some curly willow and slide the fruit between it and the glass, but that is in a low profile cube or cylinder. It's easy when you can get your fingers all the way to the bottom to adjust. If your vase it too tall and narrow you won't be able to get your hand in it to adjust the fruit as easily at the bottom. I have not tried it with acrylic, though I don't see why it wouldn't work under the same circumstances.
The fruit generally does cloud the water a bit with juice and pulp,so if you use water,you can simply spill out the water and refill it until it's clear. I would not leave the task of arranging the flowers to the wedding day.  This should be done the day before.  If your flowers are hearty they will be fine kept in a cool room. Neither you nor your wedding party should be doing anything but getting yourselves ready and enjoying the day!
Please let me know if you have any other questions.
Best Regards,
Peggy