The 5 A per-contact rating is typical for a 0.100" pitch header with tin-plated contacts — the current is limited by the contact cross-section and the temperature rise of the UL94 V-0 housing.
The right-angle through-hole mounting puts the solder tails 0.305" (7.75mm) long — enough for a standard 0.062" PCB with good through-hole fill, but the 0.095" (2.41mm) insulator height above the board means the mating interface sits low, so the mating half's shroud or strain relief must clear the board surface.