It seems like you many many version of the Adobe Lightroom catalog.
Yes you can delete them from your computer, but sure that the catalog that you are currently using is safe.
The location of the current catalog that you are using in Lightroom can be found in the catalog settings.
click on edit> catalog settings
I'm not sure why you are creating so many different catalogs. Some of them have different names, and probably contain different images. The most efficient way to use Lightroom is to have a single catalog. I'm not sure what is in your differently named catalogs. But you would be wise to spend some time looking at what is in each catalog. Then create a new catalog and import from each of the different catalogs (you probably won't need to import from all of them, but I don't know). After you have consolidated everything into a single catalog and are confident that you have everything, then you can safely delete all of these other catalogs.
I opened many catalogs as I was updating to new versions and before I realized what I was doing:-( . Is there a most efficient way to consolidate them as you suggest?
Thanks for the help.