When using ExcelApplication to create or modify charts, there appears to be an empty space for the chart title even though one wasn’t specified or the chart title is set to an empty string.
ExcelWriter will leave space for a chart title if any of the Chart.Title properties are set; this includes setting Chart.Title.Text to an empty string. This is because ExcelWriter assumes that if Chart.Title properties are being set, then there will be a chart title.
This mimics Excel’s behavior, as chart title properties cannot be accessed or modified unless there is a non-empty chart title.
To avoid having extra space for the title, only set Chart.Title properties when Chart.Title.Text is set to a non-empty value (i.e. you intend for the chart to have a title).