http://www.whypad.com/posts/sap-determine-table-for-data-element/181/

If there is one thing that SAP is not lacking in, it's database tables. 40,000+ tables is what I've heard. They've got tables of tables. Knowing which table a particular piece of data is stored in is sometimes extremely useful, essential really if you're going to do a SQVI or an SE16 query. If you're lucky, finding the table for a particular data element can be easy, if you're not lucky, well, you're really not lucky in this case :

Steps for Finding Table for a Data Element

1. From a t-code that contains your data element, click in the field for that element…here's an example of clicking in Cost Center field in T-code KS13 (Cost Center Master Data:
2. Next press F1 key to bring up Help (aka Performance Assistant)
3. In the Performance Assistant, click the Technical Information button (shown above)
4. In the technical Assistant, look for the Field Name or Data Element field and copy the value:
5. Go to the ABAP Dictionary – T-code: SE11and enter the field name into the Data Type field…be sure to select the Data type radio button, and click Display button at bottom:
6. From the Display Data Element screen, click the "Where Used" button, circled in red below:
7. Select "Table fields" (you can play around with the others, but we're looking for a table
8. Now comes the needle in the haystack search…except we've really narrowed down the haystack a lot. You can do a search (Ctrl-F) for key words that might be in your table, like "Master" for Master Data tables, etc. If you can't find the table you're looking for, you might have need to try a different data element. For instance, if you look up the data element for GL Account from T-code FB50, you get HKONT for the field name. But you won't find a Master Data table for that. You need to go to FS00 and look up the field name there, which gives you SAKNR. Using the above steps, you can easily find the Master Data table for SAKNR. Here's a shot of a data element tables list for KOSTL (Cost Centers):

Sometimes you get lucky looking up a field in the Performance Assistant and it gives you an actual table name and not a structure or view. This solves the problem neatly, but after that, you're kind of searching.

If anyone has a better method, please…really…please, let us know.

Cheers!