Total fat can include the entire fat molecule (fatty acids + glycerol backbone), but the fatty acid groups (saturated, monounsaturated, polyunsaturated) include only the associated fatty acids. The glycerol component is not typically identified by data sources and can make up roughly 5% of the total fat. A typical analysis in the software could show about 5% in the "other fats" component due to the glycerol component.
If your analysis includes more than 5% in the "Other Fats" category, this may be due to missing values in the fatty acid groups. Saturated fat and trans fat are required label nutrients, but mono and poly fats are not and therefore not always reported by manufacturers and suppliers leading to this occurrence of missing data and a larger percent of "Other Fat" than would be expected.
You can review the Spreadsheet report to view detail on reported vs unreported data for the fat components.