In the beginning (IIRC), tables had only four characters in their names. The first few characters referred to the purpose of the table, one of the character relates to the key (compare LFA1 with LFB1, MARA with MARC). Of course, SAP is a German company, so the meaningful names (of older tables) are only meaningful in German. LFA1 is the vendor master - that's Lieferant in German. Hence the "LF".Customer is Kunde - so KNA1.Fields are similarly treated, so post code is often PSTLZ - which is Postleitzahl. Mandant is German for client - so MANDT. Have a play with www.dict.cc and see what you can find. SAP being SAP, there's no hard and fast rule. Eventually, you just learn what is what. It was useful when I first arrived in a German speaking company, as I already knew a few words from my SAP experience!Though I can't help you with the naming of these tables , reason being I don't know German.But I can help you to remember with the Table Nomenclature in SAP.Follow the below points : 1. All vendor tables start with L such as lfa1, etc..2.all customer tables start with K ... Kna1, konv...3.all sales tables start with V... vbak vbap4.allmost for configuration ( related to company details tables )start with T... T001, t001w5.all bank tables start with B.. Bknf, bkpf...6.all purchasing tables start with E.. ekko, ekpo etc..7.all material tables start with M... mara, makt, marc...8.invoice related tables start with R... rbkp, rseg... And in cases where Header Data and Corresponding Line Item data Table are there ,then , Header Table name will contain Alphabet K and Line Item table name will contain P. eg EKKO (PO Header) and EKPO ( Line Item PO ) Now keeping these above detail in mind ,BSEG is a cluster table now how to learn its Indexes.just remember BS*#where values of * can be I ( for Open Items) or A ( for Closed Items)and that of # can be K ( for Vendor ) or ( D for Customer ) eg BSIK ( Open Vendor Items ) Now for learning fields , Fields ending with ZEIT is related with Time related field , ending with DATUM is related with Date related field , ending with ENGE is related with Quanity, ending with BTR or ERT or ETR is related with amount.