Tenting or wrapping your plate of meat with foil will trap the steam emanating from the meat, creating a humid environment that will soften the crust as it rests.
The concern is that without covering it, the meat will cool during this resting period. The truth is, as long as it is rested properly, it won't cool that much.
The best place to rest meat is on a cooling rack or a wooden cutting board. If you don't have either of these two items, place your meat on a plate that has been warmed up.