I made this video showing a non-scripting method for creating multiple linked records from a single text field.
You could use the same technique for your list of urls, except instead of splitting out the urls based on the new line character, you would need to split them out based on the comma.
On the other hand, a custom script would be much faster, require fewer fields, and take fewer automation runs.
If you are interested in learning scripting, this would be a good beginner project.
I decided to make a video showing one way of writing a script that does this.
Note that the script in my video will not run as an automation script. However, if enough people view, like, and comment on the video, I will probably make a follow-up video that shows how to convert the script to run as an automation.