Are these actual numbers? If so, you've got me curious! How does it work? Do you really have billions of lines of code? How many of those 580k tables are auto generated?
SAPs program environment comes with a built in editor and a relational database, and that the metadata of every table is stored in the database and the program is not stored on the file system but in the database as well. (Which makes tools like github superflous. When you edit code it gets a lock on the database).
So conveniently in SAP there is a database tables which holds all database tables and another table for all fields. Likewise there is a table for all programs and SAP stores all program lines in another database table. So you just need count the number of entries in these tables.
I am not aware of any generated tables, but maybe are some. Maybe 5%. I'd estimate that maybe half of the programs are actually generated code. Whereas "program" probably is not accurate, some of the programs are modules or function pools which are invoked by other programs.
The numbers are smaller than initially given, but still big enough for not being handled with unstructured databases.