Accidently Named all tables in my database starting with a number
In your situation, I would probably use a script something like this to generate all the sp_rename commands for me:

SELECT SCHEMA_NAME(schema_id) as schemaname, name as tablename, 
cmd = 'EXEC sp_rename ''' + SCHEMA_NAME(schema_id) + '.' + name + ''', ''' 
  + SUBSTRING(name, 6, 99) + ''';'
FROM sys.tables
WHERE type = 'U'
AND is_ms_shipped = 0
AND name LIKE '2019[_]%'


This takes the name from the sys.tables system table, and finds all the user-created tables with a name starting with 2019_. It generates a list of sp_rename commands, which you can copy into a new SSMS window and carefully review to make sure they look correct before running.

Note that this is going to break any other objects (views, triggers, stored procs,  etc.) that refer to these tables, so I hope this database is very early in development.