Table 310.15(B)(6) Can only be used for 120/240-Volt, 3-Wire, Single-Phase Dwelling Services and Feeders.
As you are using 2-2-2-4 SER this would be 4 wire so you can not use this table.
You need to use 310.16 Type SE cable contains Types RHW, RHW–2, XHHW, XHHW–2, THWN, or THWN–2 conductors so you need to know which type you have to know which column to use.
Also you will need to know your terminal temperature ratings to know which column you can use.
You must use the lowest temperature rating of the wire and terminals.
So the rating of 2 AWG aluminum is 75 amps at 60C or 90 amps at 75C
As far as the "R" I have always told that means SE round, helpful info when ordering a wet location connector.
