Try to do this way
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
}
or if you use .net core try it
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Usuario>().ToTable("Usuario");
}
Replace Usuario for your Entity Name, like a DbSet<<EntityName>> Entities without Plural