Sure! Here is a test case generator for the given problem statement about the 2xN grid and collecting the maximum number of candies:

```python
import random

def generate_test_case():
    N = random.randint(1, 100)
    
    A = [[random.randint(1, 100) for _ in range(N)] for _ in range(2)]
    
    return N, A

def format_test_case(N, A):
    input_str = f"{N}\n"
    input_str += " ".join(map(str, A[0])) + "\n"
    input_str += " ".join(map(str, A[1]))
    
    return input_str

# Example usage
N, A = generate_test_case()
test_case = format_test_case(N, A)
print(test_case)
```

This generator function `generate_test_case` will create random test cases within the constraints given in the problem statement. The function `format_test_case` formats the generated test case into the required input format for the problem. 

Each test case consists of:
1. An integer \(N\), representing the number of columns.
2. Two lists of integers of size \(N\), representing the number of candies in each cell of the 2xN grid.

You can call the `generate_test_case` function to generate a random test case and then format it using the `format_test_case` function to get a string that can be used to test your solution.