The template I linked automatically calculates hourly totals, prices given a rate and time and subtotals. I think that covers the "spreadsheet-like" capabilitie

The template I linked automatically calculates hourly totals, prices given a rate and time and subtotals. I think that covers the "spreadsheet-like" capabilities you mention. The presentation details of the template are bundled into a class file and each line item is simply: \hourrow{Date}{hours}{hourly rate} As for whether one semi-structured text file is easier to edit than another, I suppose it will have to come down to a matter of opinion.