Using EntityFrameworkCore with an existing database

I am building a new application that will connect to an existing database. I have used the reverse engineering tool and it all works OK. However I wopuld like to give my entitles and model properties more meaningful names

I tried the following in the OnModelCreating function

builder.Entity<Donor>().ToTable("personal");
builder.Entity<Donor>().Property(d => d.Id).HasColumnName("p_key");
builder.Entity<Donor>().Property(d => d.Title).HasColumnName("p_title");
builder.Entity<Donor>().Property(d => d.Surname).HasColumnName("p_surname");

However when I update the database I get  the error There is already an object named 'personal' in the database. 

I have tried to find a way of doing this andI can see that you could change the mappings with the designer in the previous version.

Any help would be much appreciated.

Thanks