Instead of using _ProductSmallBox you can use your own customized views too. here number 3 means three columns. you can change to any number as per your need.
I want to achieve the same effect, but get the following error:
'System.Web.Mvc.HtmlHelper<Nop.Web.Models.Catalog.SearchModel>' does not contain a definition for 'DataList' and the best extension method overload 'Nop.Web.Framework.UI.DataListExtensions.DataList<T>(System.Web.Mvc.HtmlHelper, System.Collections.Generic.IEnumerable<T>, int, System.Func<T,System.Web.WebPages.HelperResult>)' has some invalid arguments