Plot lines on x(time)y(percentage) axis when time is variable for each element.

[Arandomperson]

I've figured out how to do this by manually adding 1 line at a time but have no clue how I would go about doing this for the whole table at once.

[MrShorty]

With the data arranged in this way, there is no other way except to add each data series separately one at a time. You can automate this simple but tedious process using VBA, but VBA will be doing the same thing (adding and defining each data series individually).

If you rearrange the data so that you have a single row (column) with all of your unique time values (2.75, 3, 3, 3.75, etc.) and a single row (column) for each data series (with blanks for the time entries that don't apply to that data series), then you can select your entire table and insert the scatter chart in one go (and Excel should correctly interpret the ranges for the data series). I don't know if you would be allowed to rearrange the data or make a copy of the data in a different arrangement.