In creative mode, right clicking with a single empty map will replace it in your hotbar with a map, while right-clicking with multiple empty maps (2-64) will not use up any empty maps and will create a map in a different location in your inventory.
MCPE-111151 Empty map is consumed in creative mode
MC-124280 Using fire charges on TNT in creative mode consumes the fire charge
MC-143805 Can't fill an empty map in creative mode
MC-143821 Using empty map in creative mode can create additional map with ID 0
MC-16753 Glass Bottle is consumed upon right-click on a water source/cauldron in creative