Adding empty element to declared container without declaring type of element

You can take advantage of copy-list-initialization (since C++11) and just write

table.push_back({});

Before C++11 sometimes I use x.resize(x.size()+1), in C++11 or later you can use x.push_back({}).

From CLion's IntelliSense, I later found that one useful method is emplace_back(). This constructs a new object of correct type and adds it to the end of the vector.

table.emplace_back();