Ah yes, numbers and tables.  Now that I've learned how to generate
these things using computer programs, I can include lots of great
information without spending years typing:

Pi to 50,000 digits
(Source: Mathematica)

e to 50,000 digits
(Source: Mathematica)

Square roots and the golden ratio
(Source: Mathematica)

Logarithm Tables (base 10)
(Source: My own C++ program)

Natural Logarithm Tables (base e)
(Source: My own C++ program)

Interest Tables
 (Source: My own C++ program)