Is it possible to check if table value exists?

Hello, so as you can see from the question i am trying to write a script that should check if the table(tablename, 1) exists and if it doest it does something. The problem is that i dont know how to check it. the code i am trying:

if table(invtab, 1) == nil then
            --blablabla
end

i get an error attempt to call global 'table' (a table value) any suggestions?