In Reincarnated as a Slime, what are the approximate distances between locations, aka the scale of the map?
This might not be approximate but I'll mention it anyways. Before rimuru tempest showed up it might have taken them the time stamp of:

Dwargon - 2 Months
Beast Nation - 5 Months
Demon Lord Milim's Place - Fastest pace - 8-9 Months Slowest Pace - 11 Months
Holy Reuben Empire - Fastest pace - 10 Months Slowest Pace - 12-13 Months
Kingdom of Ingrasia - Fastest pace - 7 Months Slowest Pace - 9 Months
Barren Lands - Fastest pace - 13 Months Slowest Pace - 15 Months

Again this is not approximate but hope it eases the minds.