Here is the table.
You have to look at row E13, which is the standard monthly pay for PhD students with a full position in Germany. The first column is for the first year, then you advance to the second column at the beginning of the second year, and to the third column at the beginning of the fourth year.
Those are values before taxes. Clicking on the number leads you to an online calculator that estimates the value after taxes.
This amount is paid 12.5 times a year: one salary per month plus an additional half salary in November as Christmas money (Weihnachtsgeld/Sonderzahlung).
The above is valid for doctoral students with full positions, which are common in engineering. It is common in many other fields to have partial positions (50% or 65% of a position). In this case, the contract will specify a reduced number of hours per week (20.05 or 26.65 instead of 40.1 hours per week in Bayern) and the corresponding percentage will be applied to the salary before taxes. The percentage after taxes will be higher due to a reduced tax rate: there are online calculators such as this one that estimate this value.