In the desktop version of Excel, clicking one of the column headers will display the filter options. This includes the free text search box which initially gets focus. This makes it very easy for users to click, type and hit enter to filter the data.
Within Excel Online, similar functionality is available but it's much more tucked away. So more clicking and thus time is required to achieve the same result. Our users like the effectiveness of the desktop solution and would like to request a similar approach for Excel Online.