they shouldn't have been - our regs require them not to be refrigerated before sale, and Tesco are not likely to break such regs wittingly. Regs also require that cartons be stamped with advice to refrigerate them after purchase. These apparently contradictory regs are to avoid condensation forming on eggs that are brought out of a chilly environment and into a warm one, and the condensation compromising the bloom, during packing and transporting to the shop.they may have been refrigerated during transport
By all means have a go at hatching them - it'll be great if some do hatch. As someone else posted there was a news item a week or two ago about 3 out of 6 Clarence Court eggs hatching! A 50% hatch rate should be encouragement to you!