Types TPT and TST have their own column, because they come in 27AWG. That's referred to as tinsel cord. The 27AWG row of this Table is for those two types of conductors only. Notice it's empyt for the other two columns and the rows below the 27AWG row are empty for Types TPT and TST.
If you compare the two tables, you see Table 400.5(A)(1) runs from 20AWG through 2AWG (plus it has that top row for two types of conductor that come in 27AWG only). but Table 400.5(A)(2) starts at 12AWG and runs to 1000 kcmil. It would be just silly to merge these two tables for that reason alone. Another factor (and there really are several but we'll stop at two) is that Table 400.5(A)(1) does not have three temperature columns (60, 75, and 90 DegrC) but Table 400.5(A)(2) does.
It does matter. Use the adjustment factors in Table 400.5(A)(3) to modify the value(s) you obtained from Tables 400.5(A)(1) and/or 400.5(A)(2).
- Between an existing receptacle and an inlet, where the inlet provides power to an additional single receptacle outlet [400.7(A)(11)]
- Each flexible cord must be equipped with an attachment plug and energized from a receptacle or cord connector body [400.7(B)].