from typing import List


def to_chars(tokens: List[str], token_len: int, pad_char: str):
    """
    Convert each token from a list into a list of chars.
    Args:
        tokens: list of strings
        token_len: fixed num of chars for each word
    Returns:
        char_tokens: List[List[str]]: For each token in the input, convert to a list of chars (fixed len). Increase 1 more dim with respect to the input.
    """
    def convert(tok):
        chars = list(tok)
        if len(chars) < token_len:
            chars += [pad_char] * (token_len - len(chars))
        return chars[:token_len]

    char_list = list([convert(tok) for tok in tokens])
    return char_list