readtable() seems to work with your example data.
m = readtable('test.txt')
m =
4×2 table
A B
_ _
1 2
3 4
5 6
7 8
m.A is your first column.
m.B is your second column.
If the first row of your data, "A B", really isn't separated by a comma, you'll lose those variables names in your table (m.Var1 instead of m.A). If they do have a comma, your table will contain the variable names. I put a comma in your example to produce my outputs.
