Are they all the same tags? If so, you could perhaps structure it with parent-child UDTs. All tags you define on a parent UDT will be inherited by the child UDT.
One major annoyance is that you can’t change the parent of an UDT once the child is created …
So perhaps you can create an empty parent first, export your tags to XML, modify the XML by hand (with a decent text editor like Notepad++ on Windows), and import the XML again.
It’s probably enough to add the line
<Property name="UDTParentType">path/to/UDTParent</Property> per UDT to your XML, but best try with a small example first to see if everything imports nicely.