The SAP system has a data dictionary, which effectively holds data on the data in the system (meta data). The data dictionary in SAP is often referred to as transaction SE11 "Abap dictionary", for good reason: this is a very commonly used transaction that can grant you access to the why and how of data. Would you like to turn data into information ? The Abap dictionary or data dictionary is an excellent starting point.

The information that is held on tables are clearly described on the system. It's good to understand a little on how this was done. Client-dependence ? What's a data element ? A domain ? 

Direct table update methods - for problem fixing.

Use SE16 or SE16n to do small scale fixing - or use LSMW for bigger scale fixing.

The system uses tables, and a lot of them too. Good thing we have the table maintenance generator, otherwise a lot of coded logic would have to be developed for maintaining content. But the table generator can take things further...

Does your report use settings that are available on a table for which table maintenance was generated ? Why not bring this table to the selection screen ?

You have defined a transparent table, created data elements for it some of which have domains with a control table or with domain values. And now you need to do all of this again, including actual table content, for a new system. I've composed a small tool that will help you create a download file with everything you need for the table. And with the same tool, implemented at the receiving end, domains, data elements, the table with it's fields and actual content can be restored (upload). 

Would you like to compare your program with other programs or the same program in other systems ?