How to sum up columns in table.ff or how to convert it to doable form

Question

What's the 'nature' of a table.ff object in r? dim of table.ff is N ULL, and typically it is used for frequency measures. I could not find any funtion to add all columns together in order to do some statistics on resultant ' numeric vector'. str of my example of table.ff is num [1:215558488] 0 0 0 0 0 0 0 0 0 0 ...

Thanks ahead for any thoughts!