How to Check Tables And Fields In SAP Business One

1.  Login into SAP Business One client application
2. From View in the top toolbar, check/enable System Information, or by using the shortcut Ctrl+Shift+I
3. Now hover over on any document in SAP Business One such; Sales order, Journal Entries, Business Partner Master Data, ... and check the bottom tab to view the String Info, Table, and Column codes.  
4. Note down the Table name (OITM) to know its fields
5. Now you may take the table code OITM, and use it in the Query Generator, via Tools > Queries > Query Generator
6. Enter the table name in the left side top corner field in Query  Generator and press "TAB"