One for each table? One for every 2 tables? How many guests did you seat at each table? I''m trying to gauge whether or not one server for every two tables is enough.
If you are having rounds, they tend to be - 6''s, 8''s, 10''s or 11''s.
I have never really worried about numbers of servers - the venue/caterers will know what normally works. If you are doing it all DIY, I would go with 1 server per 2 tables maximum.
Most people overestimate on things like quantity of wine/staff etc that are needed.