Populate Tables of Database in DropDownList in ASP.Net

This will get you all the Tables from the

SELECT DISTINCT sys.tables.name [TableName] FROM sys.tables
INNER JOIN sys.columns  ON sys.tables.object_id = sys.columns.object_id
GROUP BY sys.tables.name, sys.columns.name

Put this in the DataTable and bind it to DropDownList

this.ddlTables.DataTextField = "TableName";
this.ddlTables.DataValueField = "TableName";
this.ddlTables.DataSource = dt;
this.ddlTables.DataBind();

And On Selected Index Change You can pass the SelectedItemValue to Query and get the table details ion some GridView.