How to drop multiple tables with common prefix in one query?
You can build up a string using the catalog views, e.g.:

DECLARE @sql NVARCHAR(MAX) = N'';

SELECT @sql += '
DROP TABLE ' 
    + QUOTENAME(s.name)
    + '.' + QUOTENAME(t.name) + ';'
    FROM sys.tables AS t
    INNER JOIN sys.schemas AS s
    ON t.[schema_id] = s.[schema_id] 
    WHERE t.name LIKE 'LG_001%';

PRINT @sql;
-- EXEC sp_executesql @sql;


Of course there are potential gotchas, for example if these tables have foreign key relationships, you'll either need to drop them first, or arrange the output to drop the tables in a certain order.

To just get the list of tables, use:

SELECT s.name, t.name 
  FROM sys.tables AS t 
  INNER JOIN sys.schemas AS s 
  ON t.[schema_id] = s.[schema_id] 
  WHERE t.name LIKE 'LG_001%';