When you see symbol it means that there is a Drop Down List. At the bottom of the list there may be a choice that says "Edit List". This choice only appears if your Administrator has given you the permission to edit the lists.
Lists are used to add structure and standardization to your data. Without lists, one user may fill in a field with "Mutual Fund" and another user might be in a hurry and just put "MF" where another may call it a "Unit Trust". Then when you want to search for a list of all Mutual Funds, you would never find them all.
People who normally do data entry may or may not be given permission to add to these lists. This is decided by the administrator. These permissions are assigned from the Admin Menu.
The Ellipse symbol drops down a Lookup List. These lists have more than one column, but can also be edited if the Administrator has given permission.