You don’t have to use regular images in your Dataset so your custom numpy arrays should be fine.
Here is a small dummy example:
class MyDataset(Dataset):
    def __init__(self, data):
        self.data = torch.from_numpy(data).float()
        
    def __getitem__(self, index):
        x = self.data[index]
        return x
    
    def __len__(self):
        return len(self.data)

I’m not sure, what your targets are, so you might want to pass them additionally to the Dataset or calculate them in __getitem__.