[Noob question] I've got about a dozen columns and about 55k rows of data to add to a fresh database made up of one table... Would it be faster to "normalize" the data and split it into several tables?

I'm making an ASP.NET MVC4 site, and I'm very new to SQL in general. I'm using a LocalDB, from what I can tell, and after creating the Model to add to a table, it takes around 20 minutes to add all the models to the table. This is a process that does not need to be done very often at all, and so 20 minutes is bearable, but I would like to know if it could be optimized at all.

I can split up the data a bit into different tables, and I will be doing that soon, but before I do, is there a speed benefit to do so, in regards to adding the data to the table?

tl;dr 12 columns over 55k rows inserting into a single new table takes 20 minutes, is there a faster way to add them? Does normalizing it speed to process up?