If the SAP system, you are working on supports the Tcode SE16N, you dont need to do a lot of stuff just to enter a data in table.
We can create database tables in SAP using transaction code SE11. A table can be manipulated by a program or manually.
When creating table, you will find a check box 'Table maintenance allowed'. If we check that option, we can manually enter entries using SE16 or table maintenance generator screen.
Go to SE11, give the table name and click on change. Then Go to utilities--> Table maintenance generator.
In the table maintenance generator screen, we should give Authorization Group, Function Group name (Function Group name can be same as table name), Maintenance type can be one step or two step, usually we will create with one step. we should give maintenance screen number. After clicking on create button, a table maintenance generator will be created.
Open SAP tables for direct maintenance
1. SE11 enter table name
2. Go to Attributes tab
3. Change the delivery class to 'L'
4. Follow the path Utilities -> Table maintenance generator
5. Change the recording routine ( bottom of the screen) to NO, or user.
6. Activate the table, do NOT recreate the table maintenance routines