This is often a cue for the caterer to ready themselves for the incoming food service. Based on your religious affiliation, you can either have your religious official conduct the prayer for the food or a loved one.
After the prayer, the MC will guide the wedding guests toward the catering area. Depending on the guest list and number of courses, this is usually an hour-long process in your wedding reception timeline and is a good place for your guest to interact over food and drinks as the afternoon progresses. This allows the wedding party to make any outfit changes if necessary, some couples may want to switch to more comfortable clothing or even cultural regalia and makeup depending on culture, and this allows them time as the guest enjoy their meal.