Extract Grid expressions from a notebook

Tabular data in notebooks is most often formatted as Grid expressions. Read the contents of "Output" cells in a notebook of boiling points and specific heats of elements and select those that are Grid expressions:

Extract data from the Grid expressions

The first argument of a Grid expression contains the data in the grid. Extract the data with First:

Post-process the data

Extracted data may require some post-processing to put it into the form you want. For example, apply QuantityMagnitude to the second column of each table to extract the numerical values of the boiling points and specific heats: