Inventory Drop

Inventory drop is a mod that allows you to drop all inventory slots at once by double tapping K (by default)

You can configure the keybind you want to use in the keybindings menu.

Esc → Options → Controls → Key binds

This is especially useful for farms and dropping useless items quickly.

Some servers may consider this cheating - I would not recommend using this on public multiplayer servers without asking permission.