Alt+F3 is the general way to add, but, as you have noticed, it requires you to select each thing to be added. Since you are assigning a name and category to each entry it is hard to get around this.
Take a look at Greg Maxey's page on
Building Blocks & AutoText. He includes an Add-In that lets you load building blocks including AutoText from a Table. You can choose one gallery at a time and load in different categories with individual names. The entry is in one column, the name in a second, and the category in a third column of the table.
Graham Mayor has a different Add-In.
Create autotext entries from a Word table by Graham Mayor, MVP. Graham's is simpler but does not allow for addition of a category. It is more designed for pre-building blocks AutoText, in my opinion.
More References (my page):
Also take a look at: