NameError: name 'input_table' is not defined

import as knio

# tables will come in as Arrow tables and can be converted to pandas data frame
input_table = knio.input_tables[0].to_pandas()

# you can manipulate or create a new pandas data frame
output_table = input_table.copy()

# to get the whole thing back you bring the pandas data frame back to Arrow
knio.output_tables[0] = knio.Table.from_pandas(output_table)

As suggested you might want to consult the Python guide and check out these examples: