Sure, let's outline the steps Gemima needs to take to add the title in a single cell at the top of her table.
Step 1: Insert a new row above the header row in the table.
Step 2: Merge the cells in the new row to form one single cell spanning the entire width of the table.
Step 3: Type the title 'Food Nutrient Content' into the single merged cell.
Step 4: Format the title cell by making the text bold and centering it horizontally within the cell.
By following these steps, Gemima will successfully add a title to her table in a single, properly formatted cell.