Calculating for a desired concentration yourself isn't hard, and you know you'll have reliable results. With this formula, you won't need the chart.

Lets use KNO3 as an example. Simply take the atomic mass of KNO3 (add up the atomic mass of 1 potassium, 1 nitrogen and 3 oxygen from your periodic table or use wikipedia):

101.10332g/mol

Then divide it by the atomic mass of NO3:

=101.10332/62.00501

If you stop here, you'll get the quantity of KNO3 in mg that it takes to raise 1L of water by 1ppm.

Moving on to larger dosing, multiply by your desired ppm of NO3 (lets say 20):

=101.10332/62.00501*20

If you stop here, you'll get the quantity of KNO3 it takes to raise 1L of water by however much NO3 you want in it.

Finally to dose a column, multiply by the number of liters that you want to dose (10 gal is about 37.8541L, use google to convert or multiply by 3.78541):

=101.10332/62.00501*20*37.8541

This ends up working out to about 1234.47mg of KNO3 to get 20ppm of NO3 in 10 gal of water. For practical purposes, call it 1.23g

If you want to make the chart, it's not much of a change to do it the other way. Simply switch the places of the two atomic masses:

=62.00501/101.10332

Multiply by the weight you're adding in mg:

=62.00501/101.10332*1000

Divide by the number of liters you're adding it to:

=(62.00501/101.10332*1000)/37.8541

This ends up being about 16.2ppm.