The current position of the export button implies a global "scope" however it's behaviour depends on the current tab.
The button should be moved to the individual tab pane.
Perhaps the button should be moved the File menu: file -> export -> [my addresses, address book, transaction log]
I don't think it's so confusing. "Export" exports whatever is in the current tab, as it currently is shown. It is close to the thing it exports. For example, if you set a filter on your transactions, that is used to filter the output.
Adding a toolbar to the individual tab panes would waste vertical space. And I don't really want to add any more buttons at the bottom either.
Adding the option to the menu as well sounds OK though...
@graingert Can you please close this now, as current master has new position for export and even no global thing anymore.