The Address Map Window is the bottom right window and shows a list of the addresses and their corresponding values. The address map is initially empty and addresses have to be manually added/defined although helpers exist to do this automatically for each poll/message shown in the other windows.
If you have to, addresses can be manually added, either singly or in bulk, using [Add Addresses] from the right click menu. You must specify a start address, the last address and the step (e.g. a step of 2 will add every alternate address. So 1000-1004 step 2 will add 1000, 1002 and 1004.
Each address in the map has a basic type, so BIT, DOUBLE, FLOAT, LONG or SHORT. These correspond to the types of data Winmodbus Master supports for modbus messages. Note: these are slightly different from the types specified in the poll definition as they do not need any indication of how they are encoded/decoded. They should correspond to the type polled for, so a poll for some sort of float (DANIEL, ROSEMOUNT, etc.) at 1000 indicates you should have FLOATs in the address map at the addresses covered by the poll.
Address values can be changed by double clicking on the address and entering a new value in the dialog that comes up.
Finally, addresses can be deleted from the right click menu. For this, multiple addresses can be selected using the mouse in conjunction with the SHIFT or CTRL key and all deleted at once.