Hello @ChrisL2070 ,
Typically if an Excel document is over 5mb it's because it has an excessive number of columns and rows, that either are or were, populated with information. For example, some customers have run into issues when trying to upload contact files because even though they deleted the unneeded columns of info, Excel still maintains those columns and that info when determining the file size. This can typically be resolved by copying what you actually need from the oversized Excel doc, and transferring it to a brand new, fresh doc. You'll likely notice a significantly smaller size when saving the new file.