Many of us that are older or those that love vintage things have pyrex or fire king or some of the older kitchen items.
This is a 8x8 inch fire king pan. I enjoy simple cakes in this pan. I don't believe there was ever a lid for this pan and it is common for people to have other size pieces with missing lids.
This is a tip how I cover my fire king and Pyrex pieces. Lay wax paper over the top and rub a spoon or the flat of your scissors to score a mark.
Follow the mark and cut out leaving one corner with a tab for lifting out.
Lay a crochet cover as a light weight to keep the wax paper in place.
Here is a close up of this pattern but it can be more simple and just a single crochet all the way or double crochet.
To make this just chain long enough for the size pan you are going to cover. Turn then single crochet or double crochet change patterns if you like. I don't use patterns when I make these I just sit and crochet so I don't have a pattern for this.
This could also be knitted. I will see if I can figure out how to write a pattern for you if you are interested, I have never written one and it might not be written properly like they write them but maybe I could make sense of it.
You could make a sewn version of this too. Sew a square of it by cutting fabric out a seam allowance more all the way around. Cut two pieces and sew three sides. Turn right side out then sew it closed and that would make cute pieces to lay over the wax paper.
I hope this helps to inspire your imagination. Grandma Donna