When creating an ERD, how can I add a set of columns

Rather than add column:type one by one, can I import a list of columns.
I need to create tables some has 300+ columns.

You may consider to use the Excel data import feature to import the columns. i.e. You can create a dummy table with few columns and then export model to Excel. After that follow the format in Excel to feed-in your data and then import it back to our software.