FYI, in the Developer version of the WAB, I noticed that when exporting the Attribute Table to CSV in IE11, Excel didn't seem to be recognizing the comma delimiters and rows would show up in a single column. I tried a workaround found in this thread on stackoverflow:
And made the following edit to the widgets/AttributeTable/Widget.js file:
And the CSV now displays as expected in Excel (2010). Hope this helps.
Update: This issue seems to not have been fixed in the 1.1 version. The workaround I used in the 1.1 version is this: