Except for the camper on the top left those are all rigging knives, designed to be used by sailors to work with cord and rope (lines), the blades are typically a sheepsfoot and a Marlin Spike, the knife blade is often serrated, the Spike is used to stick into knots to loosen them, separate strands in twisted rope, grab and pull on a cord loop, etc., sometimes they have a shackle tool or slot used to turn and open the pins in marine shackles.
Top center: British Army Knife, Joseph Rodgers, Sheffield, note that center liner extends as a flat screwdriver.
Top right: Camillus, USA.
Bottom left: Captain Curry, Sheffield.
Middle right: Ibberson, Sheffield.
Bottom right: Oooops, Chinese cheapo, copy of British Army Knife.
Here's a picture of three of the knives in open position, plus:
Top: a Spike made by tying a fancy knot on a pointy bolt.
Bottom: two Marlin Spikes with shackler slots, one adds a bottle opener.
Luis