SAP prefers that we use function modules instead of using tables. So before checking out this list, please check out the functions.

BASIS
DD03L Table fields and definitions
DD07V Domain texts
VARIT Variant texts
VARI Variant contents are in table
ICONT Icon texts
STXL, STXH Standard text table ( Used by READ_TEXT function)
T247 Multilingual month names
USZBV* Central user management tables
INFODYNP to store dynpros(screens)
APTREET German and Eglish text strings side by side
BERISVE1 Users and authorisation for users
T77S0 Table to store own variables

TRMAC Macro table
TVARV Variables stored in table
TTDTG Sapscript standard symbols
TCURV Exchange rate types for currency translation
TCURX Decimal places for currencies
TCURR Exchange Rates

FI - Financial
T052 Table for due dates and discount percentage rates
KEYS: ZTERM code, ZZTAG day limit BACK: Termin day, termin percent
T001S Table for accounting clerk names
KEYS: (knb1-)BUKRS, (knb1-)BUSAB BACK: Accounting clerk name, sap user name
TBSL Posting keys
TKA02 Buchungskreis -> Kostenrechnungskreis KOKRS ->

CO - Controlling
TKA01 Controlling area master

T800S Cost element groups
T810A Relation between cost element groups

CSKB Cost elements
CSKU Cost element text

COBK Cost document header
COEP Cost document item

CSKS Cost Center Master
CSKT Cost Center Texts


SD - Sales
VBUK SD document status
VBAK, VBAP Purchase order
VBRK, VBRP Invoice

MM - Material Management
EBAN ( Banfs ) Purchase requests:
EBKN ( Connection to SD, Sales order number )
EKKO, EKPO Purchase orders (EKKO-BSTYP = ‘F’)
EKBE Goods receipts and invoices for purchase orders:

Contracts: EKKO, EKPO ( ekko-bstyp = 'K' )
Release documents according to this contract: EKAB

T156 Movement types:
MM-> Purchasing -> Master Data -> Inforecord
MM-> Purchasing -> Master Data -> Source list

EINA Inforecord general
EINE Inforecord purchasing group specific

MCHB Batches
MSKA Blocked batch quantities

HR - Human Resources
USER_ADDR User Name, group ...
T591A - Infotype Subtypes and Zeitbindung dazu
T582A - Infotype settings overview
T510 - Amounts for tariff groups
T588Z - Dinamic events for infotypes
T588M - HR Turn on and off fields
T5CP9 - Which infotypes should transaction PACA infotype overview show
T779X - Userexit to call, whenever a PA* table is changed
T5C10 - Gemeinde Tabellen
(Abrech. Abr.Schweiz, Steuer, Q.St., Jahrlich...)
T5C2K - Quellensteuer Tabellen
T77S0 - Table for different variables
T503 - In ABART if somebody is hourly or monthly waged
T522N, T522F Defining name in the address field for the payslip "Abrechnungsformular"