虾仁 specifically means peeled, deshelled shrimp ready for cooking — what English menus call 'shrimp meat'. Famous dishes:
龙井虾仁 (Lóngjǐng xiārén, Longjing-tea shrimp, a Hangzhou specialty) and
虾仁炒蛋 (shrimp scrambled with egg). The
仁 ('kernel') is the same character used for the edible inside of nuts (
杏仁 'almond kernel').