Mary Poppin’s Magic Carpet Bag. In one simple bag she carries around lamps, mirrors, hat stands, and who knows what else.
Snoopy’s Dog House. It’s a bit hard to depict in a photo, but he has everything in there. Far more than should be able to fit, space-wise.
And the original of this trope – The TARDIS.
And because it’s Christmastime – how else do you suppose Santa fits all those gifts in his sleigh?