Your current process is passing a featureclass with a selected feature to the script. using the selected feature as input, you can use a search cursor to access the features data.
inTable = input from your model, which will be Table1
destTable = input from your model, which will be Table2
with arcpy.da.SearchCursor(inTable , Field_A) as cur:
for row in cur:
resString = 'Value 1: {} Value 2: {}'.format(row[0].split(' ')[0], row[0].split(' ')[1])
# insert into target FC
arcpy.da.InsertCursor(Table2, Field_B) as cur:
cur.insertRow(resString)
You will need to set this script up as a script tool, then drag and drop that tool it into your model and wire up the input parameters.