I have created a new table and immediately I used that table in my one of the query, but I have found that table with red underline and showing that table is invalid.
The solution is,
SQL Server Management Studio IntelliSence Local Cache:
We have to refresh IntelliSence Local Cache so that all newly created objects added in the cache and red underline will disappear.
You can refresh this IntelliSence Local Cache from the edit menu of SSMS.