len(self.table)
checks for the length of the array, so you can use if-statements to find out if the length of the list is greater than 0 (not empty):
Python 2:
if len(self.table) > 0:
#Do code here
Python 3:
if(len(self.table) > 0):
#Do code here
It's also possible to use
if self.table:
#Execute if self.table is not empty
else:
#Execute if self.table is empty
to see if the list is not empty.