code: def tables():
      t1 = pd.DataFrame({"mae": [0.1, 0.11], "mse": [0.2, 0.21]}).T
      t2 = pd.DataFrame({"mae": [0.15, 0.16], "mse": [0.25, 0.26]}).T
      t3 = pd.DataFrame({"mae": [0.25, 0.26], "mse": [0.35, 0.36]}).T
      return [t1, t2, t3]
  
imports: import pytest
  import pandas
  import numpy
  from sklearn_evaluation import NotebookCollection
  from sklearn_evaluation.nb import NotebookCollection
  from IPython.display import HTML
label_desc: Use image node_id 14 for calling a global function with example usage: tables() and returns: list