Need help interpreting this data table (provided below)
The first row for each number in the leftmost column represent alkanes with $n$ many carbons and aldehydes and ketones with $n-1$ carbons and one double bonded oxygen. These are all in the same row because if you replace a carbon with a double bonded oxygen, you wind up with the same mass once you remove the excess hydrogens. The next row is for alcohols, which have an $-\ce{OH}$ instead of a $=\ce{O}$, which leads to an increase in molar mass by 2. 

The alkane link above links to a table, which shows the boiling points with the molecular formula for each alkane.