Migration Error - Not sure why

I have been working on this for a while, and this is the third migration I am doing.

This is still an area I struggle with.  However in this case I am trying to update without deleting my database as I want to try it.  This is creating an error in dotnet method on cmd prompt as below:

System.Data.SqlClient.SqlException: There is already an object named 'ApplicationUser' in the database.
   at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
   at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
   at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady)
   at System.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean async, Int32 timeout, Boolean asyncWrite)
   at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, Boolean sendToPipe, Int32 timeout, Boolean asyncWrite, String methodName)
   at System.Data.SqlClient.SqlCommand.ExecuteNonQuery()
   at Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.Execute(IRelationalConnection connection, String executeMethod, IReadOnlyDictionary`2 parameterValues, Boolean closeConnection)
   at Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.ExecuteNonQuery(IRelationalConnection connection, IReadOnlyDictionary`2 parameterValues)
   at Microsoft.EntityFrameworkCore.Migrations.Internal.MigrationCommandExecutor.ExecuteNonQuery(IEnumerable`1 migrationCommands, IRelationalConnection connection)
   at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.Migrate(String targetMigration)
   at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.UpdateDatabase(String targetMigration, String contextType)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabase.<>c__DisplayClass0_1.<.ctor>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
ClientConnectionId:c0190636-5eed-4a8e-aade-ba45a05ed942
Error Number:2714,State:6,Class:16
There is already an object named 'ApplicationUser' in the database.

I don't understand why it is fixated on Application User and where this is in relation to the migration code.  From what I read of the migration code it is nothing to do with it.

namespace Eva804.Migrations
{
    public partial class WaterTestType : Migration
    {
        protected override void Up(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.CreateTable(
                name: "WaterTestType",
                columns: table => new
                {
                    WaterTestTypeID = table.Column<int>(nullable: false)
                        .Annotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn),
                    WaterTstType = table.Column<string>(nullable: true)
                },
                constraints: table =>
                {
                    table.PrimaryKey("PK_WaterTestType", x => x.WaterTestTypeID);
                });

            migrationBuilder.CreateTable(
                name: "WaterTestTypeParameters",
                columns: table => new
                {
                    WaterTestTypeParametersID = table.Column<int>(nullable: false)
                        .Annotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn),
                    ChemicalParameterID = table.Column<int>(nullable: true),
                    WaterTestTypeID = table.Column<int>(nullable: true)
                },
                constraints: table =>
                {
                    table.PrimaryKey("PK_WaterTestTypeParameters", x => x.WaterTestTypeParametersID);
                    table.ForeignKey(
                        name: "FK_WaterTestTypeParameters_ChemicalParameters_ChemicalParameterID",
                        column: x => x.ChemicalParameterID,
                        principalTable: "ChemicalParameters",
                        principalColumn: "ChemicalParameterID",
                        onDelete: ReferentialAction.Restrict);
                    table.ForeignKey(
                        name: "FK_WaterTestTypeParameters_WaterTestType_WaterTestTypeID",
                        column: x => x.WaterTestTypeID,
                        principalTable: "WaterTestType",
                        principalColumn: "WaterTestTypeID",
                        onDelete: ReferentialAction.Restrict);
                });

            migrationBuilder.CreateIndex(
                name: "IX_WaterTestTypeParameters_ChemicalParameterID",
                table: "WaterTestTypeParameters",
                column: "ChemicalParameterID");

            migrationBuilder.CreateIndex(
                name: "IX_WaterTestTypeParameters_WaterTestTypeID",
                table: "WaterTestTypeParameters",
                column: "WaterTestTypeID");
        }

        protected override void Down(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.DropTable(
                name: "WaterTestTypeParameters");

            migrationBuilder.DropTable(
                name: "WaterTestType");
        }
    }

The other confusing point is after reading on line various stackoverflow posts and so on they are referring to the migration table in my SQL server.  When I open this table I find it contains no data which is very confusing as I have run several migrations on this database.

Any guidance please?