You've got a lot of work to do because the list hasnt been set up properly. Each part of the name and address record should be in separate columns. So firstly, I would insert another row as row 1 by right clicking on row 1 address and down to insert. Now on the new Row 1 enter the column names of Title, First Name, Surname, Address 1, Address2, Address3, County, Postcode etc. etc.
Now click in the cell that contains your first entry. You will cut and paste bit by bit into the relevant columns but as you do it you will be writing a macro so that its just question for the next ones of hitting the shortcut keys that you will use. So, click in Cell A2 which should now be cell containing first record, up to Tools, Macro, Record New Macro, assign to keyboard and use Ctrl Shift T and OK, now start the procedure and when you've finished the first one, click on the first icon on the macro toolbar to stop it running. If you want to assign the macro to a button instead of the shortcut keys, draw a rectangle or circle, then right button on the border, add text, and put in macro or whatever you want, then right button fill with colour to make it pretty and lastly, right button, assign to macro. So that in future to run the macro and change the rest of the entries into their separate columns should be a dodle. It's still not a one push button thing, as each record has to be done separately but at least the macro will cover that if you set it up right to begin with. Hope this helps. When it's all sorted into columns, highlight the lot, save for the column headings, up to data,sort and put into chronological order by Surname, and/or whatever else you need to sort by.
Once this is done its easy to do mail merge, you just go into Word start the process, use existing list, and browse to where your Excel list is. If you need help on that, feel free to email me.