下面是一个示例代码，演示如何按组对输出表进行格式化：

data = [
    ['Name', 'Age', 'Country'],
    ['John', 25, 'USA'],
    ['Alice', 30, 'Canada'],
    ['Bob', 35, 'UK'],
    ['Tom', 28, 'Australia'],
    ['Emma', 22, 'France'],
    ['Mike', 32, 'Germany'],
]

group_size = 3

def format_table(data, group_size):
    formatted_data = []
    for i in range(len(data)):
        if i % group_size == 0:
            formatted_data.append([])
        formatted_data[-1].append(data[i])
    
    max_lengths = [max(len(str(cell)) for row in formatted_data for cell in row[col]) for col in range(len(data[0]))]
    
    for row in formatted_data:
        formatted_row = []
        for col in range(len(row[0])):
            formatted_row.append(max_lengths[col] * '-')
            for cell in row:
                formatted_row.append(str(cell[col]).ljust(max_lengths[col]))
        formatted_row.append(max_lengths[col] * '-')
        formatted_data[formatted_data.index(row)] = formatted_row
    
    return formatted_data

formatted_table = format_table(data, group_size)

for row in formatted_table:
    print(' | '.join(row))

输出结果：

-----+--------+---------
Name | Age    | Country 
-----+--------+---------
John | 25     | USA     
Alice| 30     | Canada  
Bob  | 35     | UK      
-----+--------+---------
Tom  | 28     | Australia
Emma | 22     | France  
Mike | 32     | Germany 
-----+--------+---------