SAP - How to find which SAP Classes, Interfaces and BAPIs write to a particular SAP Table in SAP GUI

1. In SAP GUI, go to /nse11 and enter your table name (e.g. Table "LFA1" for SAP Vendors).
   
2. Click display to display the table (this is just transaction SE11_OLD)
   
3. Just choose Programs, Classes/Interfaces and click Execute. You will be provided with a full list of the BAPIs, classes and interfaces that reference that table.
   
4. Alternatively you can use transaction /nse37 to search for BAPIs that have a name similar to the table or the functionality they expose (e.g. *VENDOR*).