A maintenance log only needs seven columns to be useful: date, odometer reading, service performed, parts cost, labor cost, whether a shop or DIY did the work, and notes. That is enough detail to answer when a service was done, what it cost, and who did it, without becoming a chore to fill in. The same seven columns work as a printable table or as a spreadsheet - put the column names in row 1, freeze that row, and add an eighth Total Cost column that sums parts and labor.
A paper log works only as well as your discipline: most get a few entries in the first month and then quietly stop. A spreadsheet fixes the where-is-it problem but not the did-I-remember problem, since nothing reminds you to open it.