Some of the important AX Tables

Table Names	Table Description
CustTable	The table for basic customer information
VendTable	The table for basic vendor information.
LedgerTable	The table for the general ledger that contains the chart of accounts information.
InventTable	The table for the general inventory catalog.
PurchTable	The table for purchase order creation information.
SalesTable	The table for sales order creation information.

Undersatanding InventDimId and InventTransId

InventDimId:- It is generated against the unique combination of inventory dimensions(size,color etc.).The unique combination can be found in table InventDim.

InventTransId:- It is generated against each transaction of an item and the transaction is saved in table InventTrans.This ID is generated in order to keep track of the item.



Detail explaination on InventDimId:- http://basicax.blogspot.in/2013/03/ax2012-understanding-inventdimid.html