Excel & Google Sheets

Google Sheets - IMPORTXML from multiple pages

Assuming B3 & B4 contain the urls:

={IMPORTXML(B3;"//h2");IMPORTXML(B4;"//h2")}  

You can also concatenate page numbers with a base url, as follows:

={IMPORTXML($B$2 & "1", "//section//h4[@class='item_categ']");IMPORTXML($B$2 & "2", "//section//h4[@class='item_categ']")}

– via StackOverflow

Google Sheets - Concatenate IMPORTXML results with strings

Use ARRAYFORMULA:

=ARRAYFORMULA("a-" & IMPORTXML(B2, "//@id"))

Works with multiple pages as well:

=ARRAYFORMULA("a-" & {IMPORTXML(B2 & "1", "//@id"); IMPORTXML(B2 & "2", "//@id")})

– via StackOverflow

Google Sheets - Display images extracted with IMPORTXML

Use IMAGE coupled with ARRAYFORMULA:

=ARRAYFORMULA(IMAGE(IMPORTXML(B2 & A1, "//section//div[@class='pli_img_outer']/img/@src"), 1))