The excerpt for the excel tag is not showing all of it's information. This is how it should start:
Microsoft Excel is a spreadsheet application.
but it starts with:
a spreadsheet application.
This is clearly a bug:
Surprisingly, the google-spreadsheets tag starts properly. Can it be that the excerpt text is too long?
Changed the excerpt for the excel tag to the following text:
The spreadsheet application from Microsoft.
Now it fits, see screenshot: